1
|
Lim SE, Cho S, Choi Y, Na JG, Lee J. High production of ectoine from methane in genetically engineered Methylomicrobium alcaliphilum 20Z by preventing ectoine degradation. Microb Cell Fact 2024; 23:127. [PMID: 38698430 PMCID: PMC11067125 DOI: 10.1186/s12934-024-02404-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 04/24/2024] [Indexed: 05/05/2024] Open
Abstract
BACKGROUND Methane is a greenhouse gas with a significant potential to contribute to global warming. The biological conversion of methane to ectoine using methanotrophs represents an environmentally and economically beneficial technology, combining the reduction of methane that would otherwise be combusted and released into the atmosphere with the production of value-added products. RESULTS In this study, high ectoine production was achieved using genetically engineered Methylomicrobium alcaliphilum 20Z, a methanotrophic ectoine-producing bacterium, by knocking out doeA, which encodes a putative ectoine hydrolase, resulting in complete inhibition of ectoine degradation. Ectoine was confirmed to be degraded by doeA to N-α-acetyl-L-2,4-diaminobutyrate under nitrogen depletion conditions. Optimal copper and nitrogen concentrations enhanced biomass and ectoine production, respectively. Under optimal fed-batch fermentation conditions, ectoine production proportionate with biomass production was achieved, resulting in 1.0 g/L of ectoine with 16 g/L of biomass. Upon applying a hyperosmotic shock after high-cell-density culture, 1.5 g/L of ectoine was obtained without further cell growth from methane. CONCLUSIONS This study suggests the optimization of a method for the high production of ectoine from methane by preventing ectoine degradation. To our knowledge, the final titer of ectoine obtained by M. alcaliphilum 20ZDP3 was the highest in the ectoine production from methane to date. This is the first study to propose ectoine production from methane applying high cell density culture by preventing ectoine degradation.
Collapse
Affiliation(s)
- Sang Eun Lim
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul, Republic of Korea
| | - Sukhyeong Cho
- C1 Gas Refinery R&D Center, Sogang University, Seoul, Republic of Korea
| | - Yejin Choi
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul, Republic of Korea
| | - Jeong-Geol Na
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul, Republic of Korea
| | - Jinwon Lee
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul, Republic of Korea.
- C1 Gas Refinery R&D Center, Sogang University, Seoul, Republic of Korea.
| |
Collapse
|
2
|
Yun JH, Lee H, Nam JW, Ko M, Park J, Lee DH, Lee SG, Kim HS. Unlocking synergies: Harnessing the potential of biological methane sequestration through metabolic coupling between Methylomicrobium alcaliphilum 20Z and Chlorella sp. HS2. BIORESOURCE TECHNOLOGY 2024; 399:130607. [PMID: 38499203 DOI: 10.1016/j.biortech.2024.130607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 03/09/2024] [Accepted: 03/15/2024] [Indexed: 03/20/2024]
Abstract
A halotolerant consortium between microalgae and methanotrophic bacteria could effectively remediate in situ CH4 and CO2, particularly using saline wastewater sources. Herein, Methylomicrobium alcaliphilum 20Z was demonstrated to form a mutualistic association with Chlorella sp. HS2 at a salinity level above 3.0%. Co-culture significantly enhanced the growth of both microbes, independent of initial inoculum ratios. Additionally, increased methane provision in enclosed serum bottles led to saturated methane removal. Subsequent analyses suggested nearly an order of magnitude increase in the amount of carbon sequestered in biomass in methane-fed co-cultures, conditions that also maintained a suitable cultural pH suitable for methanotrophic growth. Collectively, these results suggest a robust metabolic coupling between the two microbes and the influence of the factors other than gaseous exchange on the assembled consortium. Therefore, multi-faceted investigations are needed to harness the significant methane removal potential of the identified halotolerant consortium under conditions relevant to real-world operation scenarios.
Collapse
Affiliation(s)
- Jin-Ho Yun
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea; Department of Integrative Biotechnology, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon, Gyeonggi-do 16419, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, University of Science & Technology (UST), Daejeon 34113, Republic of Korea.
| | - Hyewon Lee
- Synthetic Biology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea; Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science & Technology (UST), Daejeon 34113, Republic of Korea.
| | - Jang-Won Nam
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, University of Science & Technology (UST), Daejeon 34113, Republic of Korea.
| | - Minji Ko
- Synthetic Biology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea; Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science & Technology (UST), Daejeon 34113, Republic of Korea.
| | - Jaehyun Park
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea.
| | - Dae-Hee Lee
- Department of Integrative Biotechnology, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon, Gyeonggi-do 16419, Republic of Korea; Synthetic Biology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea; Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science & Technology (UST), Daejeon 34113, Republic of Korea; Graduate School of Engineering Biology, Korea Advanced Institute of Science & Technology (KAIST), Daejeon 34141, Republic of Korea.
| | - Seung-Goo Lee
- Synthetic Biology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea; Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science & Technology (UST), Daejeon 34113, Republic of Korea; Graduate School of Engineering Biology, Korea Advanced Institute of Science & Technology (KAIST), Daejeon 34141, Republic of Korea.
| | - Hee-Sik Kim
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, University of Science & Technology (UST), Daejeon 34113, Republic of Korea.
| |
Collapse
|
3
|
Cho S, Lee YS, Chai H, Lim SE, Na JG, Lee J. Enhanced production of ectoine from methane using metabolically engineered Methylomicrobium alcaliphilum 20Z. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:5. [PMID: 35418141 PMCID: PMC8759281 DOI: 10.1186/s13068-022-02104-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 01/04/2022] [Indexed: 11/22/2022]
Abstract
Background Ectoine (1,3,4,5-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid) is an attractive compatible solute because of its wide industrial applications. Previous studies on the microbial production of ectoine have focused on sugar fermentation. Alternatively, methane can be used as an inexpensive and abundant resource for ectoine production by using the halophilic methanotroph, Methylomicrobium alcaliphilum 20Z. However, there are some limitations, including the low production of ectoine from methane and the limited tools for the genetic manipulation of methanotrophs to facilitate their use as industrial strains. Results We constructed M. alcaliphilum 20ZDP with a high conjugation efficiency and stability of the episomal plasmid by the removal of its native plasmid. To improve the ectoine production in M. alcaliphilum 20Z from methane, the ectD (encoding ectoine hydroxylase) and ectR (transcription repressor of the ectABC-ask operon) were deleted to reduce the formation of by-products (such as hydroxyectoine) and induce ectoine production. When the double mutant was batch cultured with methane, ectoine production was enhanced 1.6-fold compared to that obtained with M. alcaliphilum 20ZDP (45.58 mg/L vs. 27.26 mg/L) without growth inhibition. Notably, a maximum titer of 142.32 mg/L was reached by the use of an optimized medium for ectoine production containing 6% NaCl and 0.05 μM of tungsten without hydroxyectoine production. This result demonstrates the highest ectoine production from methane to date. Conclusions Ectoine production was significantly enhanced by the disruption of the ectD and ectR genes in M. alcaliphilum 20Z under optimized conditions favoring ectoine accumulation. We demonstrated effective genetic engineering in a methanotrophic bacterium, with enhanced production of ectoine from methane as the sole carbon source. This study suggests a potentially transformational path to commercial sugar-based ectoine production. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13068-022-02104-2.
Collapse
|