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Lee YG, Kang NK, Kim C, Tran VG, Cao M, Yoshikuni Y, Zhao H, Jin YS. Self-Buffering system for Cost-Effective production of lactic acid from glucose and xylose using Acid-Tolerant Issatchenkia orientalis. Bioresour Technol 2024; 399:130641. [PMID: 38552861 DOI: 10.1016/j.biortech.2024.130641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 03/24/2024] [Accepted: 03/24/2024] [Indexed: 04/05/2024]
Abstract
This study presents a cost-effective strategy for producing organic acids from glucose and xylose using the acid-tolerant yeast, Issatchenkia orientalis. I. orientalis was engineered to produce lactic acid from xylose, and the resulting strain, SD108XL, successfully converted sorghum hydrolysates into lactic acid. In order to enable low-pH fermentation, a self-buffering strategy, where the lactic acid generated by the SD108XL strain during fermentation served as a buffer, was developed. As a result, the SD108 strain produced 67 g/L of lactic acid from 73 g/L of glucose and 40 g/L of xylose, simulating a sugar composition of sorghum biomass hydrolysates. Moreover, techno-economic analysis underscored the efficiency of the self-buffering strategy in streamlining the downstream process, thereby reducing production costs. These results demonstrate the potential of I. orientalis as a platform strain for the cost-effective production of organic acids from cellulosic hydrolysates.
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Affiliation(s)
- Ye-Gi Lee
- Department of Bio and Fermentation Convergence Technology and Center for Bioconvergence, Kookmin University, Seoul 02707, Korea; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Nam Kyu Kang
- Department of Chemical Engineering, College of Engineering, Kyung Hee University, Yongin, 17104, Republic of Korea
| | - Chanwoo Kim
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Vinh G Tran
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Mingfeng Cao
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yasuo Yoshikuni
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Huimin Zhao
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yong-Su Jin
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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Kang HB, Kim SH, Lee JH, Lee HC, Kang NK, Lee JH. MRI-based volumetric tumor parameters before and during chemoradiation predict tumor recurrence and patient survival in locally advanced cervical cancer: a subgroup analysis of a phase II prospective trial. Int J Clin Oncol 2024; 29:620-628. [PMID: 38530569 DOI: 10.1007/s10147-024-02490-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 02/12/2024] [Indexed: 03/28/2024]
Abstract
BACKGROUND This subgroup analysis of a prospective phase II trial aimed to identify valuable and accessible prognostic factors for overall survival (OS) and progression-free survival (PFS) of patients with locally advanced cervical cancer (LACC). METHODS Patients with FIGO II to IVA cervical cancer were assessed in this study. All patients underwent concurrent chemoradiotherapy (CCRT) followed by brachytherapy. Tumor parameters based on MRI scans before and during CCRT were evaluated for Overall survival (OS) and Progression-free survival (PFS). RESULTS A total of 86 patients were included in this analysis with a median follow-up period of 31.7 months. Three-year OS and PFS rates for all patients were 87.1% and 76.5%, respectively. Univariate Cox regression analysis showed that restaging tumor size (rTS) over 2.55 cm (p < 0.001), initial tumor volume (iTV) over 55.99 cc (p < 0.001), downstaging (p = 0.042), and restaging tumor volume (rTV) over 6.25 cc (p = 0.006) were significantly associated with OS. rTS (p < 0.001), iTV (p < 0.001), downstaging (p = 0.027), and rTV (p < 0.001) were identified as significant prognostic factors for PFS. In the stepwise multivariable analysis, only rTS > 2.55 cm showed statistically significant with OS (HR: 5.47, 95% CI 1.80-9.58, p = 0.035) and PFS (HR: 3.83, 95% CI 1.50-11.45; p = 0.025). CONCLUSIONS Initial tumor size and restaging tumor volume that are easily accessible during radiotherapy provide valuable prognostic information for cervical cancer. MRI-based measurable volumetric scoring system can be readily applied in real-world practice of cervical cancer. CLINICAL TRIAL INFORMATION This study is a subgroup analysis of prospective trial registered at ClinicalTrials.gov Identifier: NCT02993653.
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Affiliation(s)
- Han Byul Kang
- Department of Radiation Oncology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Sung Hwan Kim
- Department of Radiation Oncology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Joo Hwan Lee
- Department of Radiation Oncology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Hyo Chun Lee
- Department of Radiation Oncology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Nam Kyu Kang
- Department of Radiation Oncology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Jong Hoon Lee
- Department of Radiation Oncology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
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Kang NK, Sung SY, Kim SH, Jeon YW, Suh YJ, Lee JH. Hypofractionated Partial Breast Irradiation With Intensity-Modulated Radiotherapy in Early Breast Cancer or Carcinoma In Situ: An Investigational Short-Term Analysis. J Breast Cancer 2024; 27:79-90. [PMID: 38529590 DOI: 10.4048/jbc.2023.0296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 02/12/2024] [Accepted: 03/21/2024] [Indexed: 03/27/2024] Open
Abstract
PURPOSE This study aimed to analyze the treatment outcomes and adverse effects of moderately hypofractionated partial breast irradiation (PBI) in patients with early breast cancer. METHODS In total, 473 patients with early breast cancer or carcinoma in situ were diagnosed with Tis or T1N0 disease and underwent PBI following breast-conserving surgery. All histologic tumor types, close surgical margins within 1 mm of the tumor, and multifocal tumors were included in this study. A radiation dose of 50 Gy in 20 fractions was delivered over 4 weeks using intensity-modulated radiotherapy technique. Dosimetric data, recurrence patterns, survival outcomes, and adverse events were retrospectively analyzed. RESULTS During a median follow-up of 28.9 months, seven patients (1.5%) experienced ipsilateral breast tumor recurrence (IBTR). Two patients had regional recurrence, four patients developed contralateral breast cancer, and no distant metastases were observed. The locoregional recurrence rate in the ipsilateral breast was 1.8%. Two deaths occurred during the follow-up period, but were not attributed to breast cancer. The 2-year disease-free survival and 2-year overall survival rates were was 94.0% and 99.8%, respectively. Acute adverse events occurred in 131 patients (27.1%), and were distributed among all grades, with only two patients (0.4%) experiencing grade 3 events. Late adverse events were noted in 16 patients (3.4%), and were distributed among all grades, including grade 3 events in four patients (0.8%). No grade 4 or 5 events were observed. CONCLUSION Hypofractionated PBI demonstrated favorable IBTR rates in patients with early breast cancer, with low incidence of acute and late toxicities in the short-term analysis.
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Affiliation(s)
- Nam Kyu Kang
- Department of Radiation Oncology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Soo-Yoon Sung
- Department of Radiation Oncology, Eunpyeong St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Sung Hwan Kim
- Department of Radiation Oncology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Ye Won Jeon
- Department of Surgery, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Young Jin Suh
- Department of Surgery, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Jong Hoon Lee
- Department of Radiation Oncology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
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Kang NK, Chau THT, Lee EY. Engineered methane biocatalysis: strategies to assimilate methane for chemical production. Curr Opin Biotechnol 2024; 85:103031. [PMID: 38101295 DOI: 10.1016/j.copbio.2023.103031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 11/17/2023] [Accepted: 11/21/2023] [Indexed: 12/17/2023]
Abstract
Methane (CH4), one of the greenhouse gases, is considered a promising feedstock for the biological production of fuels and chemicals. Although recent studies have demonstrated the capability of methanotrophs to convert CH4 into various bioproducts by metabolic engineering, the productivity has not reached commercial levels. As such, there is a growing interest in synthetic methanotrophic systems as an alternative. This review summarizes the strategies for enhancing native CH4 assimilation and discusses the challenges for the construction of synthetic methanotrophy into nonmethanotrophic industrial strains. Additionally, we suggest a mixed heterotrophic approach that integrates CH4 assimilation with glucose and xylose metabolism to improve productivity. The synthetic methanotrophic system presented in this review could pave the way for sustainable and efficient biomanufacturing using CH4.
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Affiliation(s)
- Nam Kyu Kang
- Department of Chemical Engineering (BK21 FOUR Integrated Engineering Program), Kyung Hee University, 17104 Yongin-si, Gyeonggi-do, South Korea
| | - Tin Hoang Trung Chau
- Department of Chemical Engineering (BK21 FOUR Integrated Engineering Program), Kyung Hee University, 17104 Yongin-si, Gyeonggi-do, South Korea
| | - Eun Yeol Lee
- Department of Chemical Engineering (BK21 FOUR Integrated Engineering Program), Kyung Hee University, 17104 Yongin-si, Gyeonggi-do, South Korea.
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Koh HG, Cho JM, Jeon S, Chang YK, Lee B, Kang NK. Transcriptional insights into Chlorella sp. ABC-001: a comparative study of carbon fixation and lipid synthesis under different CO 2 conditions. Biotechnol Biofuels Bioprod 2023; 16:113. [PMID: 37454088 PMCID: PMC10350272 DOI: 10.1186/s13068-023-02358-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 06/11/2023] [Indexed: 07/18/2023]
Abstract
BACKGROUND Microalgae's low tolerance to high CO2 concentrations presents a significant challenge for its industrial application, especially when considering the utilization of industrial exhaust gas streams with high CO2 content-an economically and environmentally attractive option. Therefore, the objectives of this study were to investigate the metabolic changes in carbon fixation and lipid accumulation of microalgae under ambient air and high CO2 conditions, deepen our understanding of the molecular mechanisms driving these processes, and identify potential target genes for metabolic engineering in microalgae. To accomplish these goals, we conducted a transcriptomic analysis of the high CO2-tolerant strain, Chlorella sp. ABC-001, under two different carbon dioxide levels (ambient air and 10% CO2) and at various growth phases. RESULTS Cells cultivated with 10% CO2 exhibited significantly better growth and lipid accumulation rates, achieving up to 2.5-fold higher cell density and twice the lipid content by day 7. To understand the relationship between CO2 concentrations and phenotypes, transcriptomic analysis was conducted across different CO2 conditions and growth phases. According to the analysis of differentially expressed genes and gene ontology, Chlorella sp. ABC-001 exhibited the development of chloroplast organelles during the early exponential phase under high CO2 conditions, resulting in improved CO2 fixation and enhanced photosynthesis. Cobalamin-independent methionine synthase expression was also significantly elevated during the early growth stage, likely contributing to the methionine supply required for various metabolic activities and active proliferation. Conversely, the cells showed sustained repression of carbonic anhydrase and ferredoxin hydrogenase, involved in the carbon concentrating mechanism, throughout the cultivation period under high CO2 conditions. This study also delved into the transcriptomic profiles in the Calvin cycle, nitrogen reductase, and lipid synthesis. Particularly, Chlorella sp. ABC-001 showed high expression levels of genes involved in lipid synthesis, such as glycerol-3-phosphate dehydrogenase and phospholipid-diacylglycerol acyltransferase. These findings suggest potential targets for metabolic engineering aimed at enhancing lipid production in microalgae. CONCLUSIONS We expect that our findings will help understand the carbon concentrating mechanism, photosynthesis, nitrogen assimilation, and lipid accumulation metabolisms of green algae according to CO2 concentrations. This study also provides insights into systems metabolic engineering of microalgae for improved performance in the future.
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Affiliation(s)
- Hyun Gi Koh
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Jun Muk Cho
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Seungjib Jeon
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Yong Keun Chang
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Bongsoo Lee
- Department of Microbial Biotechnology, College of Science and Technology, Mokwon University, 88 Doanbuk-ro, Seo-gu, Daejeon, 35349, Republic of Korea.
| | - Nam Kyu Kang
- Department of Chemical Engineering, College of Engineering, Kyung Hee University, Yongin, 17104, Republic of Korea.
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Lee YG, Kim C, Kuanyshev N, Kang NK, Fatma Z, Wu ZY, Cheng MH, Singh V, Yoshikuni Y, Zhao H, Jin YS. Cas9-Based Metabolic Engineering of Issatchenkia orientalis for Enhanced Utilization of Cellulosic Hydrolysates. J Agric Food Chem 2022; 70:12085-12094. [PMID: 36103687 DOI: 10.1021/acs.jafc.2c04251] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Issatchenkia orientalis, exhibiting high tolerance against harsh environmental conditions, is a promising metabolic engineering host for producing fuels and chemicals from cellulosic hydrolysates containing fermentation inhibitors under acidic conditions. Although genetic tools for I. orientalis exist, they require auxotrophic mutants so that the selection of a host strain is limited. We developed a drug resistance gene (cloNAT)-based genome-editing method for engineering any I. orientalis strains and engineered I. orientalis strains isolated from various sources for xylose fermentation. Specifically, xylose reductase, xylitol dehydrogenase, and xylulokinase from Scheffersomyces stipitis were integrated into an intended chromosomal locus in four I. orientalis strains (SD108, IO21, IO45, and IO46) through Cas9-based genome editing. The resulting strains (SD108X, IO21X, IO45X, and IO46X) efficiently produced ethanol from cellulosic and hemicellulosic hydrolysates even though the pH adjustment and nitrogen source were not provided. As they presented different fermenting capacities, selection of a host I. orientalis strain was crucial for producing fuels and chemicals using cellulosic hydrolysates.
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Affiliation(s)
- Ye-Gi Lee
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, United States
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul 02707, South Korea
| | - Chanwoo Kim
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Nurzhan Kuanyshev
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, United States
| | - Nam Kyu Kang
- Department of Chemical Engineering, Kyung Hee University, Yongin-si, Gyeonggi-do 17104, South Korea
| | - Zia Fatma
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Zong-Yen Wu
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Ming-Hsun Cheng
- Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Vijay Singh
- Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yasuo Yoshikuni
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Huimin Zhao
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, United States
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yong-Su Jin
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, United States
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Kang NK, Baek K, Koh HG, Atkinson CA, Ort DR, Jin YS. Microalgal metabolic engineering strategies for the production of fuels and chemicals. Bioresour Technol 2022; 345:126529. [PMID: 34896527 DOI: 10.1016/j.biortech.2021.126529] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/02/2021] [Accepted: 12/03/2021] [Indexed: 06/14/2023]
Abstract
Microalgae are promising sustainable resources because of their ability to convert CO2 into biofuels and chemicals directly. However, the industrial production and economic feasibility of microalgal bioproducts are still limited. As such, metabolic engineering approaches have been undertaken to enhance the productivities of microalgal bioproducts. In the last decade, impressive advances in microalgae metabolic engineering have been made by developing genetic engineering tools and multi-omics analysis. This review presents comprehensive microalgal metabolic pathways and metabolic engineering strategies for producing lipids, long chain-polyunsaturated fatty acids, terpenoids, and carotenoids. Additionally, promising metabolic engineering approaches specific to target products are summarized. Finally, this review discusses current challenges and provides future perspectives for the effective production of chemicals and fuels via microalgal metabolic engineering.
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Affiliation(s)
- Nam Kyu Kang
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Kwangryul Baek
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Hyun Gi Koh
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Christine Anne Atkinson
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Donald R Ort
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Global Change and Photosynthesis Research Unit, Agricultural Research Service, United States Department of Agriculture, Urbana, IL, USA; Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Yong-Su Jin
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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Ryu AJ, Jeong BR, Kang NK, Jeon S, Sohn MG, Yun HJ, Lim JM, Jeong SW, Park YI, Jeong WJ, Park S, Chang YK, Jeong KJ. Safe-Harboring based novel genetic toolkit for Nannochloropsis salina CCMP1776: Efficient overexpression of transgene via CRISPR/Cas9-Mediated Knock-in at the transcriptional hotspot. Bioresour Technol 2021; 340:125676. [PMID: 34365302 DOI: 10.1016/j.biortech.2021.125676] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 07/23/2021] [Accepted: 07/24/2021] [Indexed: 06/13/2023]
Abstract
Transgene expression in microalgae can be hampered by transgene silencing and unstable expression due to position effects. To overcome this, "safe harboring" transgene expression system was established for Nannochloropsis. Initially, transformants were obtained expressing a sfGFP reporter, followed by screening for high expression of sfGFP with fluorescence-activated cell sorter (FACS). 'T1' transcriptional hotspot was identified from a mutant showing best expression of sfGFP, but did not affect growth or lipid contents. By using a Cas9 editor strain, FAD12 gene, encoding Δ12-fatty acid desaturase (FAD12), was successfully knocked-in at the T1 locus, resulting in significantly higher expression of FAD12 than those of random integration. Importantly, the "safe harbored" FAD12 transformants showed four-fold higher production of linoleic acid (LA), the product of FAD12, leading to 1.5-fold increase in eicosapentaenoic acid (EPA). This safe harboring principle provide excellent proof of the concept for successful genetic/metabolic engineering of microalgae and other organisms.
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Affiliation(s)
- Ae Jin Ryu
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; Advanced Biomass R&D Center (ABC), KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Byeong-Ryool Jeong
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea; Single-Cell Center, Qingdao Institute of BioEnergy and Bioprocess Technology, Qingdao, Shandong 266101, China
| | - Nam Kyu Kang
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; Advanced Biomass R&D Center (ABC), KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; Carl. R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Seungjib Jeon
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; Advanced Biomass R&D Center (ABC), KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Min Gi Sohn
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Hyo Jin Yun
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Jong Min Lim
- Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Seok Won Jeong
- Department of Biological Sciences, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Republic of Korea
| | - Youn-Il Park
- Department of Biological Sciences, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Republic of Korea
| | - Won Joong Jeong
- Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Sunghoon Park
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Yong Keun Chang
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; Advanced Biomass R&D Center (ABC), KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Ki Jun Jeong
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea; Institute for the BioCentury, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
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Kim M, Jeon S, Kang NK, Lee HG, Shin WS, Koh HG, Yun JH, Ahn CY, Oh HM, Chang YK. Molecular analysis of sugar transporters and glycolysis pathways in Ettlia sp. under heterotrophy using fructose and glucose. Biotechnol J 2021; 17:e2100214. [PMID: 34669258 DOI: 10.1002/biot.202100214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 10/11/2021] [Accepted: 10/12/2021] [Indexed: 11/11/2022]
Abstract
Fructophilic behavior in microalgae is a rare trait that could benefit biorefineries by enabling substitution of carbon source with fructose, and our previous study identified that Ettlia sp. prefers fructose relative to glucose. In this study, by analyzing the transcription levels of genes related to sugar transport and the glycolysis pathway, the fructose utilization of Ettlia sp. was investigated. In a fructose-containing medium, the expression levels of fructokinase (EttFRK3) and glucokinase (EttGCK1 and EttGCK2) genes were significantly upregulated in heterotrophic cultivation of Ettlia sp. under fructose supplementation conditions. Further, a sugar transporter (EttSTF11) was significantly upregulated by 3.2-fold in 1 day, and this increase was analogous to the specific growth rate exhibited by the species. Subsequent cultivation tests with multi-sugar sources also showed a significant upregulation of EttSTF11 relative to other treatments without fructose. A phylogenetic tree derived from the analysis of different transporters of interest identified that EttSTF11 was adjacent to reference fructose transporters with a high bootstrap value of 71. Given that the transmembrane domains of EttSTF11 were analogous to those of reference fructose transporter genes, EttSTF11 appeared to play a critical role in fructose consumption and metabolism in Ettlia sp.
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Affiliation(s)
- Minsik Kim
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Daejeon, 34141, Republic of Korea.,Cell Factory Research Center, Korea Research Institute for Bioscience and Bioengineering (KRIBB), 125 Gwahak-ro, Daejeon, 34141, Republic of Korea
| | - Seungjib Jeon
- Research Institute of Industrial Technology Convergence, Korea Institute of Industrial Technology (KITECH), 143 Hanggaul-ro, Ansan, Gyeonggi-do, 15588, Republic of Korea
| | - Nam Kyu Kang
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.,DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Hyung-Gwan Lee
- Cell Factory Research Center, Korea Research Institute for Bioscience and Bioengineering (KRIBB), 125 Gwahak-ro, Daejeon, 34141, Republic of Korea
| | - Won-Sub Shin
- Advanced Biomass R&D Center, 291 Daehak-ro, Daejeon, 34141, Republic of Korea
| | - Hyun Gi Koh
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.,DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Jin-Ho Yun
- Cell Factory Research Center, Korea Research Institute for Bioscience and Bioengineering (KRIBB), 125 Gwahak-ro, Daejeon, 34141, Republic of Korea
| | - Chi-Yong Ahn
- Cell Factory Research Center, Korea Research Institute for Bioscience and Bioengineering (KRIBB), 125 Gwahak-ro, Daejeon, 34141, Republic of Korea
| | - Hee-Mock Oh
- Cell Factory Research Center, Korea Research Institute for Bioscience and Bioengineering (KRIBB), 125 Gwahak-ro, Daejeon, 34141, Republic of Korea
| | - Yong Keun Chang
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Daejeon, 34141, Republic of Korea.,Advanced Biomass R&D Center, 291 Daehak-ro, Daejeon, 34141, Republic of Korea
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10
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Kang NK, Lee JW, Ort DR, Jin YS. L-malic acid production from xylose by engineered Saccharomyces cerevisiae. Biotechnol J 2021; 17:e2000431. [PMID: 34390209 DOI: 10.1002/biot.202000431] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 07/14/2021] [Accepted: 07/28/2021] [Indexed: 11/07/2022]
Abstract
L-malic acid is widely used in the food, chemical, and pharmaceutical industries. Here, we report on production of malic acid from xylose, the second most abundant sugar in lignocellulosic hydrolysates, by engineered Saccharomyces cerevisiae. To enable malic acid production in a xylose-assimilating S. cerevisiae, we overexpressed PYC1 and PYC2, coding for pyruvate carboxylases, a truncated MDH3 coding for malate dehydrogenase, and SpMAE1, coding for a Schizosaccharomyces pombe malate transporter. Additionally, both the ethanol and glycerol-producing pathways were blocked to enhance malic acid production. The resulting strain produced malic acid from both glucose and xylose, but it produced much higher titers of malic acid from xylose than glucose. Interestingly, the engineered strain had higher malic acid yield from lower concentrations (10 g/L) of xylose, with no ethanol production, than from higher xylose concentrations (20 g/L and 40 g/L). As such, a fed-batch culture maintaining xylose concentrations at low levels was conducted and 61.2 g/L of malic acid was produced, with a productivity of 0.32 g/L∙h. These results represent successful engineering of S. cerevisiae for the production of malic acid from xylose, confirming that that xylose offers the efficient production of various biofuels and chemicals by engineered S. cerevisiae. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Nam Kyu Kang
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Jae Won Lee
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Donald R Ort
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Departments of Plant Biology and Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Yong-Su Jin
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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11
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Jeon S, Koh HG, Cho JM, Kang NK, Chang YK. Enhancement of lipid production in Nannochloropsis salina by overexpression of endogenous NADP-dependent malic enzyme. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102218] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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12
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Lee H, Shin WS, Kim YU, Jeon S, Kim M, Kang NK, Chang YK. Enhancement of Lipid Production under Heterotrophic Conditions by Overexpression of an Endogenous bZIP Transcription Factor in Chlorella sp. HS2. J Microbiol Biotechnol 2020; 30:1597-1606. [PMID: 32807753 PMCID: PMC9728203 DOI: 10.4014/jmb.2005.05048] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/17/2020] [Accepted: 07/26/2020] [Indexed: 12/15/2022]
Abstract
Transcription factor engineering to regulate multiple genes has shown promise in the field of microalgae genetic engineering. Here, we report the first use of transcription factor engineering in Chlorella sp. HS2, thought to have potential for producing biofuels and bioproducts. We identified seven endogenous bZIP transcription factors in Chlorella sp. HS2 and named them HSbZIP1 through HSbZIP7. We overexpressed HSbZIP1, a C-type bZIP transcription factor, in Chlorella sp. HS2 with the goal of enhancing lipid production. Phenotype screening under heterotrophic conditions showed that all transformants exhibited increased fatty acid production. In particular, HSbZIP1 37 and 58 showed fatty acid methyl ester (FAME) yields of 859 and 1,052 mg/l, respectively, at day 10 of growth under heterotrophic conditions, and these yields were 74% and 113% higher, respectively, than that of WT. To elucidate the mechanism underlying the improved phenotypes, we identified candidate HSbZIP1-regulated genes via transcription factor binding site analysis. We then selected three genes involved in fatty acid synthesis and investigated mRNA expression levels of the genes by qRTPCR. The result revealed that the possible HSbZIP1-regulated genes involved in fatty acid synthesis were upregulated in the HSbZIP1 transformants. Taken together, our results demonstrate that HSbZIP1 can be utilized to improve lipid production in Chlorella sp. HS2 under heterotrophic conditions.
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Affiliation(s)
- Hansol Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 344, Republic of Korea
| | - Won-Sub Shin
- Advanced Biomass R&D Center, Daejeon 34141, Republic of Korea
| | - Young Uk Kim
- Advanced Biomass R&D Center, Daejeon 34141, Republic of Korea
| | - Seungjib Jeon
- Advanced Biomass R&D Center, Daejeon 34141, Republic of Korea,Human Convergence Technology Group, Korea Institute of Industrial Technology (KITECH), Ansan 15629, Republic of Korea
| | - Minsik Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 344, Republic of Korea,Advanced Biomass R&D Center, Daejeon 34141, Republic of Korea
| | - Nam Kyu Kang
- Advanced Biomass R&D Center, Daejeon 34141, Republic of Korea,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA,Corresponding authors N.K.Kang Phone: +1-217-607-3151 E-mail:
| | - Yong Keun Chang
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 344, Republic of Korea,Advanced Biomass R&D Center, Daejeon 34141, Republic of Korea,Y.K.Chang Phone: +82-42-350-3927 Fax: +82-42-350-3910 E-mail:
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13
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Ryu AJ, Kang NK, Jeon S, Hur DH, Lee EM, Lee DY, Jeong BR, Chang YK, Jeong KJ. Development and characterization of a Nannochloropsis mutant with simultaneously enhanced growth and lipid production. Biotechnol Biofuels 2020; 13:38. [PMID: 32158502 PMCID: PMC7057510 DOI: 10.1186/s13068-020-01681-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 02/13/2020] [Indexed: 05/24/2023]
Abstract
BACKGROUND The necessity to develop high lipid-producing microalgae is emphasized for the commercialization of microalgal biomass, which is environmentally friendly and sustainable. Nannochloropsis are one of the best industrial microalgae and have been widely studied for their lipids, including high-value polyunsaturated fatty acids (PUFAs). Many reports on the genetic and biological engineering of Nannochloropsis to improve their growth and lipid contents have been published. RESULTS We performed insertional mutagenesis in Nannochloropsis salina, and screened mutants with high lipid contents using fluorescence-activated cell sorting (FACS). We isolated a mutant, Mut68, which showed improved growth and a concomitant increase in lipid contents. Mut68 exhibited 53% faster growth rate and 34% higher fatty acid methyl ester (FAME) contents after incubation for 8 days, resulting in a 75% increase in FAME productivity compared to that in the wild type (WT). By sequencing the whole genome, we identified the disrupted gene in Mut68 that encoded trehalose-6-phosphate (T6P) synthase (TPS). TPS is composed of two domains: TPS domain and T6P phosphatase (TPP) domain, which catalyze the initial formation of T6P and dephosphorylation to trehalose, respectively. Mut68 was disrupted at the TPP domain in the C-terminal half, which was confirmed by metabolic analyses revealing a great reduction in the trehalose content in Mut68. Consistent with the unaffected N-terminal TPS domain, Mut68 showed moderate increase in T6P that is known for regulation of sugar metabolism, growth, and lipid biosynthesis. Interestingly, the metabolic analyses also revealed a significant increase in stress-related amino acids, including proline and glutamine, which may further contribute to the Mut68 phenotypes. CONCLUSION We have successfully isolated an insertional mutant showing improved growth and lipid production. Moreover, we identified the disrupted gene encoding TPS. Consistent with the disrupted TPP domain, metabolic analyses revealed a moderate increase in T6P and greatly reduced trehalose. Herein, we provide an excellent proof of concept that the selection of insertional mutations via FACS can be employed for the isolation of mutants with improved growth and lipid production. In addition, trehalose and genes encoding TPS will provide novel targets for chemical and genetic engineering, in other microalgae and organisms as well as Nannochloropsis.
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Affiliation(s)
- Ae Jin Ryu
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Advanced Biomass R&D Center (ABC), KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Nam Kyu Kang
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Present Address: Carl. R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Seungjib Jeon
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Advanced Biomass R&D Center (ABC), KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Dong Hoon Hur
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Eun Mi Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, 08826 Republic of Korea
| | - Do Yup Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, 08826 Republic of Korea
| | - Byeong-ryool Jeong
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Present Address: School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 Korea
- Present Address: Single-Cell Center, Qingdao Institute of BioEnergy and Bioprocess Technology (QIBEBT), Qingdao, 266101 Shandong China
| | - Yong Keun Chang
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Advanced Biomass R&D Center (ABC), KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Ki Jun Jeong
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Institute for the BioCentury, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
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14
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Koh HG, Kang NK, Kim EK, Suh W, Park WK, Lee B, Chang YK. Isolation and Characterization of Novel Chlorella Species with Cold Resistance and High Lipid Accumulation for Biodiesel Production. J Microbiol Biotechnol 2019; 29:952-961. [PMID: 31154744 DOI: 10.4014/1904.04008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Chlorella spp. are green algae that are found across wide-ranging habitats from deserts to arctic regions, with various strains having adapted to survive under diverse environmental conditions. In this study, two novel Chlorella strains (ABC-002, ABC-008) were isolated from a freshwater lake in South Korea during the winter season and examined for possible use in the biofuel production process. The comparison of ABC-002 and ABC-008 strains with Chlorella vulgaris UTEX265 under two different temperatures (10°C, 25°C) revealed their cold-tolerant phenotypes as well as high biomass yields. The maximum quantum yields of UTEX25, ABC- 002, and ABC-008 at 10°C were 0.5594, 0.6747, and 0.7150, respectively, providing evidence of the relatively higher cold-resistance capabilities of these two strains. Furthermore, both the biomass yields and lipid content of the two novel strains were found to be higher than those of UTEX265; the overall lipid productivities of ABC-002 and ABC-008 were 1.7 ~ 2.8 fold and 1.6 ~ 4.2 fold higher compared to that of UTEX265, respectively. Thus, the high biomass and lipid productivity over a wide range of temperatures indicate that C. vulgaris ABC-002 and ABC-008 are promising candidates for applications in biofuel productions via outdoor biomass cultivation.
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Affiliation(s)
- Hyun Gi Koh
- Advanced Biomass R&D Center (ABC), KAIST, Daejeon 34141, Republic of Korea
| | - Nam Kyu Kang
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Eun Kyung Kim
- Advanced Biomass R&D Center (ABC), KAIST, Daejeon 34141, Republic of Korea
| | - William Suh
- Advanced Biomass R&D Center (ABC), KAIST, Daejeon 34141, Republic of Korea
| | - Won-Kun Park
- Department of Chemistry and Energy Engineering, Sangmyung University, Seoul 03016, Republic of Korea
| | - Bongsoo Lee
- Department of Microbial and Nano Materials, College of Science and Technology, Mokwon University, Daejeon 35349, Republic of Korea
| | - Yong Keun Chang
- Advanced Biomass R&D Center (ABC), KAIST, Daejeon 34141, Republic of Korea.,Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
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15
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Park DW, Lee YJ, Chang W, Park JH, Lee KH, Kim YH, Kang NK, Chung JW, Jang HY, Ahn S, Kim H, Jeong SH, Kim JW, Jang ES. Diagnostic performance of a point shear wave elastography (pSWE) for hepatic fibrosis in patients with autoimmune liver disease. PLoS One 2019; 14:e0212771. [PMID: 30856201 PMCID: PMC6411150 DOI: 10.1371/journal.pone.0212771] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 02/08/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND & AIMS Elastography point quantification is a convenient method for measuring liver stiffness. It can be performed simultaneously with conventional ultrasonography. This study aimed to evaluate its diagnostic performance for assessing hepatic fibrosis in patients with autoimmune liver disease (AILD), including autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC). METHODS The diagnostic performance of elastography point quantification (ElastPQ) was evaluated and compared with that of serum fibrosis markers, including the aspartate aminotransferase to platelet ratio index (APRI) and fibrosis-4 (FIB-4), using the receiver operating characteristics analysis with histologic evaluation as the reference standard. RESULTS In 49 AIH patients, sensitivity and specificity of ElastPQ were 93.6% and 44.4%, respectively, for significant fibrosis (≥ F2, cutoff 4.47 kPa), and 63.6% and 86.8% for cirrhosis (F4, cutoff 9.28 kPa). In 41 PBC patients, they were 81.8% and 73.3%, respectively, for significant fibrosis (≥ F2, cutoff 5.56 kPa), and 100% and 81.6%, respectively, for advanced fibrosis (≥ F3, cutoff 6.04 kPa). The areas under the receiver operating characteristic curves of ElastPQ for significant fibrosis (0.77, 95% CI 0.67-0.86) and cirrhosis (0.81, 95% CI 0.65-0.96) were higher than those of APRI and FIB-4 in AILD patients. According to the multivariable analysis, histological activity, steatosis, and body max index (BMI) were not significant factors that influenced the result of ElastPQ. CONCLUSIONS ElastPQ exhibited better diagnostic performance-without the influence of confounding factors-for assessing hepatic fibrosis in AILD patients than serum fibrosis markers.
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Affiliation(s)
- Dong Won Park
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Yoon Jin Lee
- Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Won Chang
- Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Ji Hoon Park
- Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Kyoung Ho Lee
- Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Young Hoon Kim
- Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Nam Kyu Kang
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Jung Wha Chung
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Hee Yoon Jang
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Soomin Ahn
- Department of Pathology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Haeryoung Kim
- Department of Pathology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Sook-Hyang Jeong
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Jin-Wook Kim
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - Eun Sun Jang
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
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16
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Kang NK, Kim EK, Sung MG, Kim YU, Jeong BR, Chang YK. Increased biomass and lipid production by continuous cultivation of Nannochloropsis salina transformant overexpressing a bHLH transcription factor. Biotechnol Bioeng 2019; 116:555-568. [PMID: 30536876 PMCID: PMC6590115 DOI: 10.1002/bit.26894] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 11/22/2018] [Accepted: 12/06/2018] [Indexed: 12/28/2022]
Abstract
Microalgae are promising feedstocks for sustainable and eco-friendly production of biomaterials, which can be improved by genetic engineering. It is also necessary to optimize the processes to produce biomaterials from engineered microalgae. We previously reported that genetic improvements of an industrial microalga Nannochloropsis salina by overexpressing a basic helix-loop-helix transcription factor (NsbHLH2). These transformants showed an improved growth and lipid production particularly during the early phase of culture under batch culture. However, they had faster uptake of nutrients, resulting in earlier starvation and reduced growth during the later stages. We attempted to optimize the growth and lipid production by growing one of the transformants in continuous culture with variable dilution rate and feed nitrogen concentration. Relative to wild-type, NsbHLH2 transformant consumed more nitrate at a high dilution rate (0.5 day -1 ), and had greater biomass production. Subsequently, nitrogen limitation at continuous cultivation led to an increased fatty acid methyl ester production by 83.6 mg l -1 day -1 . To elucidate genetic mechanisms, we identified the genes containing E-boxes, known as binding sites for bHLH transcription factors. Among these, we selected 18 genes involved in the growth and lipid metabolism, and revealed their positive contribution to the phenotypes via quantitative real-time polymerase chain reaction. These results provide proof-of-concept that NsbHLH2 can be used to produce biomass and lipids.
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Affiliation(s)
- Nam Kyu Kang
- Advanced Biomass R&D Center, Yuseong-gu, Daejeon, Republic of Korea
| | - Eun Kyung Kim
- Advanced Biomass R&D Center, Yuseong-gu, Daejeon, Republic of Korea
| | - Min-Gyu Sung
- Department of Chemical and Biomolecular Engineering, KAIST, Yuseong-gu, Daejeon, Republic of Korea
| | - Young Uk Kim
- Advanced Biomass R&D Center, Yuseong-gu, Daejeon, Republic of Korea
| | - Byeong-Ryool Jeong
- Department of Chemical and Biomolecular Engineering, KAIST, Yuseong-gu, Daejeon, Republic of Korea
| | - Yong Keun Chang
- Advanced Biomass R&D Center, Yuseong-gu, Daejeon, Republic of Korea.,Department of Chemical and Biomolecular Engineering, KAIST, Yuseong-gu, Daejeon, Republic of Korea
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17
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Koh HG, Kang NK, Jeon S, Shin SE, Jeong BR, Chang YK. Heterologous synthesis of chlorophyll b in Nannochloropsis salina enhances growth and lipid production by increasing photosynthetic efficiency. Biotechnol Biofuels 2019; 12:122. [PMID: 31114631 PMCID: PMC6515666 DOI: 10.1186/s13068-019-1462-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 05/04/2019] [Indexed: 05/16/2023]
Abstract
BACKGROUND Chlorophylls play important roles in photosynthesis, and thus are critical for growth and related metabolic pathways in photosynthetic organisms. They are particularly important in microalgae, emerging as the next generation feedstock for biomass and biofuels. Nannochloropsis are industrial microalgae for these purposes, but are peculiar in that they lack accessory chlorophylls. In addition, the localization of heterologous proteins to the chloroplast of Nannochloropsis has not been fully studied, due to the secondary plastid surrounded by four membranes. This study addressed questions of correct localization and functional benefits of heterologous expression of chlorophyllide a oxygenase from Chlamydomonas (CrCAO) in Nannochloropsis. RESULTS We cloned CrCAO from Chlamydomonas, which catalyzes oxidation of Chla producing Chlb, and overexpressed it in N. salina to reveal effects of the heterologous Chlb for photosynthesis, growth, and lipid production. For correct localization of CrCAO into the secondary plastid in N. salina, we added the signal-recognition sequence and the transit peptide (cloned from an endogenous chloroplast-localized protein) to the N terminus of CrCAO. We obtained two transformants that expressed CrCAO and produced Chlb. They showed improved growth under medium light (90 μmol/m2/s) conditions, and their photosynthetic efficiency was increased compared to WT. They also showed increased expression of certain photosynthetic proteins, accompanied by an increased maximum electron-transfer rate up to 15.8% and quantum yields up to 17%, likely supporting the faster growth. This improved growth resulted in increased biomass production, and more importantly lipid productivity particularly with medium light. CONCLUSIONS We demonstrated beneficial effects of heterologous expression of CrCAO in Chlb-less organism N. salina, where the newly produced Chlb enhanced photosynthesis and growth. Accordingly, transformants showed improved production of biomass and lipids, important traits of microalgae from the industrial perspectives. Our transformants are the first Nannochloropsis cells that produced Chlb in the whole evolutionary path. We also succeeded in delivering a heterologous protein into the secondary plastid for the first time in Nannochloropsis. Taken together, our data showed that manipulation of photosynthetic pigments, including Chlb, can be employed in genetic improvements of microalgae for production of biofuels and other biomaterials.
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Affiliation(s)
- Hyun Gi Koh
- Advanced Biomass R&D Center, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Nam Kyu Kang
- Advanced Biomass R&D Center, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Present Address: Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Seungjib Jeon
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Sung-Eun Shin
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Present Address: LG Chem, 188 Munji-ro, Yuseong-gu, Daejeon, 34122 Republic of Korea
| | - Byeong-ryool Jeong
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Yong Keun Chang
- Advanced Biomass R&D Center, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
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Koh HG, Kang NK, Kim EK, Jeon S, Shin SE, Lee B, Chang YK. Advanced multigene expression system for Nannochloropsis salina using 2A self-cleaving peptides. J Biotechnol 2018; 278:39-47. [PMID: 29715488 DOI: 10.1016/j.jbiotec.2018.04.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 04/25/2018] [Accepted: 04/26/2018] [Indexed: 11/19/2022]
Abstract
Even though there has been much interest in genetic engineering of microalgae, its progress has been slow due to the difficulty and limitation of available techniques. Currently, genetic modification in most microalgal strains is confined to single gene transformation. Here, a multigene expression system for the oleaginous model strain Nannochloropsis salina was developed with glycine-serine-glycine spacer linked 2A self-cleaving peptides (2A) for the first time. An efficiency test of the four most widely used 2As revealed that two different types of 2As T2A and E2A have the best performance in N. salina with a maximum cleavage rate of nearly 45%. The system was able to express the linked sequence of the selection marker shble and the fluorescence protein sfCherry with intact functions. Because 2A enabled multigene expression in the single cassette form, the use of 2A also reduced the vector size, which along with the stronger promoter resulted in a 9-fold increase in the transformation efficiency. Furthermore, confirmative screening accuracy of more than 90% was observed. Hence, the 2A applied vector system is expected to be beneficial in microalgal research field because it enables multigene expression as well as offering improved transformation and screening efficiency.
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Affiliation(s)
- Hyun Gi Koh
- Department of Chemical and Biomolecular Engineering, KAIST, Daejeon 34141, Republic of Korea.
| | - Nam Kyu Kang
- Advanced Biomass R&D Center (ABC), Daejeon 34141, Republic of Korea.
| | - Eun Kyung Kim
- Advanced Biomass R&D Center (ABC), Daejeon 34141, Republic of Korea.
| | - Seungjib Jeon
- Department of Chemical and Biomolecular Engineering, KAIST, Daejeon 34141, Republic of Korea.
| | - Sung-Eun Shin
- Department of Chemical and Biomolecular Engineering, KAIST, Daejeon 34141, Republic of Korea.
| | - Bongsoo Lee
- Department of Chemical and Biomolecular Engineering, KAIST, Daejeon 34141, Republic of Korea.
| | - Yong Keun Chang
- Department of Chemical and Biomolecular Engineering, KAIST, Daejeon 34141, Republic of Korea; Advanced Biomass R&D Center (ABC), Daejeon 34141, Republic of Korea.
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Jeon S, Lim JM, Lee HG, Shin SE, Kang NK, Park YI, Oh HM, Jeong WJ, Jeong BR, Chang YK. Current status and perspectives of genome editing technology for microalgae. Biotechnol Biofuels 2017; 10:267. [PMID: 29163669 PMCID: PMC5686953 DOI: 10.1186/s13068-017-0957-z] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 11/04/2017] [Indexed: 05/25/2023]
Abstract
Genome editing techniques are critical for manipulating genes not only to investigate their functions in biology but also to improve traits for genetic engineering in biotechnology. Genome editing has been greatly facilitated by engineered nucleases, dubbed molecular scissors, including zinc-finger nuclease (ZFN), TAL effector endonuclease (TALEN) and clustered regularly interspaced palindromic sequences (CRISPR)/Cas9. In particular, CRISPR/Cas9 has revolutionized genome editing fields with its simplicity, efficiency and accuracy compared to previous nucleases. CRISPR/Cas9-induced genome editing is being used in numerous organisms including microalgae. Microalgae have been subjected to extensive genetic and biological engineering due to their great potential as sustainable biofuel and chemical feedstocks. However, progress in microalgal engineering is slow mainly due to a lack of a proper transformation toolbox, and the same problem also applies to genome editing techniques. Given these problems, there are a few reports on successful genome editing in microalgae. It is, thus, time to consider the problems and solutions of genome editing in microalgae as well as further applications of this exciting technology for other scientific and engineering purposes.
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Affiliation(s)
- Seungjib Jeon
- Advanced Biomass Research and Development Center (ABC), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Jong-Min Lim
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Hyung-Gwan Lee
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Sung-Eun Shin
- LG Chem, 188 Munji-ro, Yuseong-gu, Daejeon, 34122 Republic of Korea
| | - Nam Kyu Kang
- Advanced Biomass Research and Development Center (ABC), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Youn-Il Park
- Department of Biological Sciences, Chungnam National University, Daejeon, 34134 Republic of Korea
| | - Hee-Mock Oh
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Won-Joong Jeong
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Byeong-ryool Jeong
- Advanced Biomass Research and Development Center (ABC), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Yong Keun Chang
- Advanced Biomass Research and Development Center (ABC), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
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Kwon S, Kang NK, Koh HG, Shin SE, Lee B, Jeong BR, Chang YK. Enhancement of biomass and lipid productivity by overexpression of a bZIP transcription factor in Nannochloropsis salina. Biotechnol Bioeng 2017; 115:331-340. [PMID: 28976541 DOI: 10.1002/bit.26465] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 09/11/2017] [Accepted: 09/29/2017] [Indexed: 11/12/2022]
Abstract
Microalgae are considered as excellent platforms for biomaterial production that can replace conventional fossil fuel-based fuels and chemicals. Genetic engineering of microalgae is prerequisite to maximize production of materials and to reduce costs for the production. Transcription factors (TFs) are emerging as key regulators of metabolic pathways to enhance production of molecules for biofuels and other materials. TFs with the basic leucine zipper (bZIP) domain have been known as stress regulators and are associated with lipid metabolism in plants. We overexpressed a bZIP TF, NsbZIP1, in Nannochloropsis salina, and found that transformants showed enhanced growth with concomitant increase in lipid contents. The improved phenotypes were also notable under stress conditions including N limitation and high salt. To understand the mechanism underlying improved phenotypes, we analyzed expression patterns of predicted target genes involved in lipid metabolism via quantitative RT-PCR, confirming increases transcript levels. NsbZIP1 appeared to be one of type C bZIPs in plants that has been known to regulate lipid metabolism under stress. Taken together, we demonstrated that NsbZIP1 could improve both growth and lipid production, and TF engineering can serve as an excellent genetic engineering tool for production of biofuels and biomaterials in microalgae.
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Affiliation(s)
- Sohee Kwon
- Department of Chemical and Biomolecular Engineering, Daejeon, Republic of Korea
| | - Nam Kyu Kang
- Department of Chemical and Biomolecular Engineering, Daejeon, Republic of Korea
| | - Hyun Gi Koh
- Department of Chemical and Biomolecular Engineering, Daejeon, Republic of Korea
| | - Sung-Eun Shin
- Department of Chemical and Biomolecular Engineering, Daejeon, Republic of Korea
| | - Bongsoo Lee
- Department of Chemical and Biomolecular Engineering, Daejeon, Republic of Korea
| | - Byeong-Ryool Jeong
- Department of Chemical and Biomolecular Engineering, Daejeon, Republic of Korea
| | - Yong Keun Chang
- Department of Chemical and Biomolecular Engineering, Daejeon, Republic of Korea.,Advanced Biomass R&D Center (ABC), Yuseong-gu, Daejeon, Republic of Korea
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Kang NK, Kim EK, Kim YU, Lee B, Jeong WJ, Jeong BR, Chang YK. Increased lipid production by heterologous expression of AtWRI1 transcription factor in Nannochloropsis salina. Biotechnol Biofuels 2017; 10:231. [PMID: 29046718 PMCID: PMC5635583 DOI: 10.1186/s13068-017-0919-5] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 09/30/2017] [Indexed: 05/03/2023]
Abstract
BACKGROUND Genetic engineering of microalgae is necessary to produce economically feasible strains for biofuel production. Current efforts are focused on the manipulation of individual metabolic genes, but the outcomes are not sufficiently stable and/or efficient for large-scale production of biofuels and other materials. Transcription factors (TFs) are emerging as good alternatives for engineering of microalgae, not only to increase production of biomaterials but to enhance stress tolerance. Here, we investigated an AP2 type TF Wrinkled1 in Arabidopsis (AtWRI1) known as a key regulator of lipid biosynthesis in plants, and applied it to industrial microalgae, Nannochloropsis salina. RESULTS We expressed AtWRI1 TF heterologously in N. salina, named NsAtWRI1, in an effort to re-enact its key regulatory function of lipid accumulation. Stable integration AtWRI1 was confirmed by RESDA PCR, and its expression was confirmed by Western blotting using the FLAG tag. Characterizations of transformants revealed that the neutral and total lipid contents were greater in NsAtWRI1 transformants than in WT under both normal and stress conditions from day 8. Especially, total lipid contents were 36.5 and 44.7% higher in NsAtWRI1 2-3 than in WT under normal and osmotic stress condition, respectively. FAME contents of NsAtWRI1 2-3 were also increased compared to WT. As a result, FAME yield of NsAtWRI1 2-3 was increased to 768 mg/L/day, which was 64% higher than that of WT under the normal condition. We identified candidates of AtWRI1-regulated genes by searching for the presence of the AW-box in promoter regions, among which lipid metabolic genes were further analyzed by qRT-PCR. Overall, qRT-PCR results on day 1 indicated that AtWRI1 down-regulated TAGL and DAGK, and up-regulated PPDK, LPL, LPGAT1, and PDH, resulting in enhanced lipid production in NsAtWRI1 transformants from early growth phase. CONCLUSION AtWRI1 TF regulated several genes involved in lipid synthesis in N. salina, resulting in enhancement of neutral lipid and FAME production. These findings suggest that heterologous expression of AtWRI1 TF can be utilized for efficient biofuel production in industrial microalgae.
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Affiliation(s)
- Nam Kyu Kang
- Department of Chemical and Biomolecular Engineering, KAIST, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Eun Kyung Kim
- Advanced Biomass R&D Center, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Young Uk Kim
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125, Gwahak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Bongsoo Lee
- Department of Chemical and Biomolecular Engineering, KAIST, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Won-Joong Jeong
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125, Gwahak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Byeong-ryool Jeong
- Department of Chemical and Biomolecular Engineering, KAIST, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Yong Keun Chang
- Department of Chemical and Biomolecular Engineering, KAIST, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Advanced Biomass R&D Center, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
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Shin SE, Koh HG, Kang NK, Suh WI, Jeong BR, Lee B, Chang YK. Isolation, phenotypic characterization and genome wide analysis of a Chlamydomonas reinhardtii strain naturally modified under laboratory conditions: towards enhanced microalgal biomass and lipid production for biofuels. Biotechnol Biofuels 2017; 10:308. [PMID: 29296121 PMCID: PMC5740574 DOI: 10.1186/s13068-017-1000-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 12/14/2017] [Indexed: 05/21/2023]
Abstract
BACKGROUND Microalgal strain development through genetic engineering has received much attention as a way to improve the traits of microalgae suitable for biofuel production. However, there are still some limitations in application of genetically modified organisms. In this regard, there has been recent interest in the isolation and characterization of superior strains naturally modified and/or adapted under a certain condition and on the interpretation of phenotypic changes through the whole genome sequencing. RESULTS In this study, we isolated and characterized a novel derivative of C. reinhardtii, whose phenotypic traits diverged significantly from its ancestral strain, C. reinhardtii CC-124. This strain, designated as CC-124H, displayed cell population containing increased numbers of larger cells, which resulted in an increased biomass productivity compared to its ancestor CC-124. CC-124H was further compared with the CC-124 wild-type strain which underwent long-term storage under low light condition, designated as CC-124L. In an effort to evaluate the potential of CC-124H for biofuel production, we also found that CC-124H accumulated 116 and 66% greater lipids than that of the CC-124L, after 4 days under nitrogen and sulfur depleted conditions, respectively. Taken together, our results revealed that CC-124H had significantly increased fatty acid methyl ester (FAME) yields that were 2.66 and 1.98 times higher than that of the CC-124L at 4 days after the onset of cultivation under N and S depleted conditions, respectively, and these higher FAME yields were still maintained by day 8. We next analyzed single nucleotide polymorphisms (SNPs) and insertion/deletions (indels) based on the whole genome sequencing. The result revealed that of the 44 CDS region alterations, 34 resulted in non-synonymous substitutions within 33 genes which may mostly be involved in cell cycle, division or proliferation. CONCLUSION Our phenotypic analysis, which emphasized lipid productivity, clearly revealed that CC-124H had a dramatically enhanced biomass and lipid content compared to the CC-124L. Moreover, SNPs and indels analysis enabled us to identify 34 of non-synonymous substitutions which may result in phenotypic changes of CC-124H. All of these results suggest that the concept of adaptive evolution combined with genome wide analysis can be applied to microalgal strain development for biofuel production.
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Affiliation(s)
- Sung-Eun Shin
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Present Address: LG Chem, 188 Munji-ro, Yuseong-gu, Daejeon, 34122 Republic of Korea
| | - Hyun Gi Koh
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Nam Kyu Kang
- Advanced Biomass R&D Center, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - William I. Suh
- Advanced Biomass R&D Center, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Byeong-ryool Jeong
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Bongsoo Lee
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Yong Keun Chang
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Advanced Biomass R&D Center, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
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Shin SE, Lim JM, Koh HG, Kim EK, Kang NK, Jeon S, Kwon S, Shin WS, Lee B, Hwangbo K, Kim J, Ye SH, Yun JY, Seo H, Oh HM, Kim KJ, Kim JS, Jeong WJ, Chang YK, Jeong BR. CRISPR/Cas9-induced knockout and knock-in mutations in Chlamydomonas reinhardtii. Sci Rep 2016; 6:27810. [PMID: 27291619 PMCID: PMC4904240 DOI: 10.1038/srep27810] [Citation(s) in RCA: 196] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 05/25/2016] [Indexed: 01/20/2023] Open
Abstract
Genome editing is crucial for genetic engineering of organisms for improved traits, particularly in microalgae due to the urgent necessity for the next generation biofuel production. The most advanced CRISPR/Cas9 system is simple, efficient and accurate in some organisms; however, it has proven extremely difficult in microalgae including the model alga Chlamydomonas. We solved this problem by delivering Cas9 ribonucleoproteins (RNPs) comprising the Cas9 protein and sgRNAs to avoid cytotoxicity and off-targeting associated with vector-driven expression of Cas9. We obtained CRISPR/Cas9-induced mutations at three loci including MAA7, CpSRP43 and ChlM, and targeted mutagenic efficiency was improved up to 100 fold compared to the first report of transgenic Cas9-induced mutagenesis. Interestingly, we found that unrelated vectors used for the selection purpose were predominantly integrated at the Cas9 cut site, indicative of NHEJ-mediated knock-in events. As expected with Cas9 RNPs, no off-targeting was found in one of the mutagenic screens. In conclusion, we improved the knockout efficiency by using Cas9 RNPs, which opens great opportunities not only for biological research but also industrial applications in Chlamydomonas and other microalgae. Findings of the NHEJ-mediated knock-in events will allow applications of the CRISPR/Cas9 system in microalgae, including "safe harboring" techniques shown in other organisms.
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Affiliation(s)
- Sung-Eun Shin
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Jong-Min Lim
- Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
| | - Hyun Gi Koh
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Eun Kyung Kim
- Advanced Biomass R&D Center (ABC), KAIST, Daejeon 34141, Republic of Korea
| | - Nam Kyu Kang
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Seungjib Jeon
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Sohee Kwon
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Won-Sub Shin
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Bongsoo Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Kwon Hwangbo
- Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
- Department of Biological Science, Chungnam National University (CNU), Daejeon 34134, Republic of Korea
| | - Jungeun Kim
- Center for Genome Engineering, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Chemistry, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - Sung Hyeok Ye
- Center for Genome Engineering, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Basic science, IBS school, Korea University of Science and Technology (UST), Seoul 08826, Republic of Korea
| | - Jae-Young Yun
- Center for Genome Engineering, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
| | - Hogyun Seo
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University (KNU), Daegu 41566, Republic of Korea
| | - Hee-Mock Oh
- Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
| | - Kyung-Jin Kim
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University (KNU), Daegu 41566, Republic of Korea
| | - Jin-Soo Kim
- Center for Genome Engineering, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Chemistry, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - Won-Joong Jeong
- Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
| | - Yong Keun Chang
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
- Advanced Biomass R&D Center (ABC), KAIST, Daejeon 34141, Republic of Korea
| | - Byeong-ryool Jeong
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
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Park BB, Park CH, Nho IY, Kim HS, Kang NK, Chang SI, Kim JM. Prevalence and clinical features of hypersensitivity reaction to contrast media after prescreening skin test. Allergy Asthma Respir Dis 2016. [DOI: 10.4168/aard.2016.4.6.442] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Bo Bae Park
- Department of Internal Medicine, Sung-Ae General Hospital, Seoul, Korea
| | - Chang Han Park
- Department of Internal Medicine, Sung-Ae General Hospital, Seoul, Korea
| | - In Young Nho
- Department of Internal Medicine, Sung-Ae General Hospital, Seoul, Korea
| | - Hae Sung Kim
- Department of Internal Medicine, Sung-Ae General Hospital, Seoul, Korea
| | - Nam Kyu Kang
- Department of Internal Medicine, Sung-Ae General Hospital, Seoul, Korea
| | - Suk Il Chang
- Department of Internal Medicine, Sung-Ae General Hospital, Seoul, Korea
| | - Jang Min Kim
- Department of Radiology, Sung-Ae General Hospital, Seoul, Korea
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Wickramasuriya SS, Yi YJ, Kim JC, Yoo J, Kang NK, Heo JM. Erratum to: A review of canola meal as an alternative feed ingredient for ducks. J Anim Sci Technol 2015; 57:38. [PMID: 26488222 PMCID: PMC4603810 DOI: 10.1186/s40781-015-0071-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - Young-Joo Yi
- Division of Biotechnology, College of Environmental & Bioresources, Chonbuk National University, Iksan-si 570-752, Jeollabuk-do, Republic of Korea
| | - Jae Cheol Kim
- Pork Innovation, Department of Agriculture and Food, South Perth, WA 6151 Australia
| | - Jaehong Yoo
- Division of Animal and Dairy Science, Chungnam National University, Daejeon, 305-764 Republic of Korea
| | - Nam Kyu Kang
- Division of Animal and Dairy Science, Chungnam National University, Daejeon, 305-764 Republic of Korea
| | - Jung Min Heo
- Division of Animal and Dairy Science, Chungnam National University, Daejeon, 305-764 Republic of Korea
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Wickramasuriya SS, Yi YJ, Yoo J, Kang NK, Heo JM. A review of canola meal as an alternative feed ingredient for ducks. J Anim Sci Technol 2015; 57:29. [PMID: 26473064 PMCID: PMC4607012 DOI: 10.1186/s40781-015-0062-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 08/07/2015] [Indexed: 11/10/2022]
Abstract
This review provides an overview of the published data on the canola meal and its suitability for duck as an alternative plant-origin protein source to soybean meal. Canola meal is a legume origin protein source containing comparable amino acid profile to soybean meal and rich in essential minerals and vitamins. Nonetheless, it is known to contain less in energy content than soybean meal. Factors like field conditions and processing methods creates compositional variations among canola meal. Presence of anti-nutritional factors such as phenolic substances, phytate and glucosinolates which are known to reduce growth performance in livestock animals, are the major drawbacks for canola meal to be a competitive plant-origin protein source in the feed industry. This review is focused to address i) nutritional characteristics and feeding value of canola meal for ducks and ii) impacts of feeding canola meal on performances of ducks.
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Affiliation(s)
| | - Young-Joo Yi
- />Division of Biotechnology, College of Environmental & Bioresources, Chonbuk National University, Iksan-si, Jeollabuk-do 570-752 Republic of Korea
| | - Jaehong Yoo
- />Division of Animal and Dairy Science, Chungnam National University, Daejeon, 305-764 Republic of Korea
| | - Nam Kyu Kang
- />Division of Animal and Dairy Science, Chungnam National University, Daejeon, 305-764 Republic of Korea
| | - Jung Min Heo
- />Division of Animal and Dairy Science, Chungnam National University, Daejeon, 305-764 Republic of Korea
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Kang NK, Lee B, Shin SE, Jeon S, Park MS, Yang JW. Use of conditioned medium for efficient transformation and cost-effective cultivation of Nannochloropsis salina. Bioresour Technol 2015; 181:231-7. [PMID: 25656867 DOI: 10.1016/j.biortech.2015.01.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 01/08/2015] [Accepted: 01/09/2015] [Indexed: 05/09/2023]
Abstract
The oleaginous microalga Nannochloropsis sp. has been spotlighted as a promising candidate in genetic engineering research for biodiesel production. However, one of the major bottlenecks in the genetic manipulation against Nannochloropsis sp. is low transformation efficiency. Based on the idea that they grow rapidly in broth culture, the effect of conditioned medium on colonization and transformation efficiency of Nannochloropsis salina was investigated. Cells grown on agar plates with 20-40% conditioned medium produced colonies that were approximately 2.3-fold larger than cells grown without conditioned medium. More importantly, the transformation efficiency was about 2-fold greater on plates with 30% conditioned medium relative to those without conditioned medium. In addition, FAME productivity in liquid cultures with 100% conditioned medium increased up to 20% compared with cultures of control medium. These results suggest that conditioned medium can be applied for efficient transformation and cost-effective cultivation of N. salina for biodiesel production.
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Affiliation(s)
- Nam Kyu Kang
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Bongsoo Lee
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Sung-Eun Shin
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Seungjib Jeon
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Min S Park
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea; Advanced Biomass R&D Center, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Ji-Won Yang
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea; Advanced Biomass R&D Center, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
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Kang NK, Jeon S, Kwon S, Koh HG, Shin SE, Lee B, Choi GG, Yang JW, Jeong BR, Chang YK. Effects of overexpression of a bHLH transcription factor on biomass and lipid production in Nannochloropsis salina. Biotechnol Biofuels 2015; 8:200. [PMID: 26628914 PMCID: PMC4666162 DOI: 10.1186/s13068-015-0386-9] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 11/16/2015] [Indexed: 05/02/2023]
Abstract
BACKGROUND Microalgae are considered promising alternative energy sources because they consume CO2 and accumulate large amounts of lipids that can be used as biofuel. Nannochloropsis is a particularly promising microalga due to its high growth rate and lipid content, and the availability of genomic information. Transcription factors (TFs) are global regulators of biological pathways by up- or down-regulation of related genes. Among these, basic helix-loop-helix (bHLH) TFs regulate growth, development, and stress responses in plants and animals, and have been identified in microalgae. We identified two bHLH TFs in the genome of N. salina CCMP1776, NsbHLH1, and NsbHLH2, and characterized functions of NsbHLH2 that may be involved in growth and nutrient uptake. RESULTS We obtained NsbHLH2 overexpressing transformants of N. salina CCMP1776 by particle bombardment and confirmed that these were stable transformants. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting using antibodies against the FLAG tag that was attached at the end of the coding sequence confirmed the expression of the NsbHLH2 protein under various culture conditions. The qRT-PCR results also indicated that the endogenous and transgenic expression of NsbHLH2 was reduced under stressed conditions. Overexpression of NsbHLH2 led to increased growth rate in the early growth period, and concomitantly higher nutrient uptake, than wild type (WT). These enhanced growth and nutrient uptake resulted in increased productivities of biomass and FAME. For example, one of the transformants, NsbHLH2 3-6, showed increased biomass productivity by 36 % under the normal condition, and FAME productivity by 33 % under nitrogen limitation condition. Conclusively, the improved growth in the transformants can be associated with the enhanced nutrient uptake. We are currently assessing their potential for scale-up cultivation with positive outcomes. CONCLUSION Overexpression of NsbHLH2 led to enhanced growth rate and nutrient uptake during the early growth phase, and increased biomass and FAME productivity, especially in the later period under normal and stressed conditions. Based on these results, we postulate that NsbHLH2 can be employed for the industrial production of biodiesel from N. salina.
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Affiliation(s)
- Nam Kyu Kang
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Seungjib Jeon
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Sohee Kwon
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Hyun Gi Koh
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Sung-Eun Shin
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Bongsoo Lee
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Gang-Guk Choi
- />Advanced Biomass R&D Center, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Ji-Won Yang
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Byeong-ryool Jeong
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Yong Keun Chang
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
- />Advanced Biomass R&D Center, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
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Kang NK, Lee B, Choi GG, Moon M, Park MS, Lim J, Yang JW. Enhancing lipid productivity of Chlorella vulgaris using oxidative stress by TiO2 nanoparticles. KOREAN J CHEM ENG 2014. [DOI: 10.1007/s11814-013-0258-6] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kim YS, Hwang SO, Lee KH, An ME, Lim KS, Kang NK, Song KS, Yoon JH, Park KS, Choe KH. Aneurysm of the Right Coronary Artery with Acute Myocardial Infarction after Blunt Chest Trauma : A Case Report. Korean Circ J 1994. [DOI: 10.4070/kcj.1994.24.2.324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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