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Lu Q, Liu JZ. Enhanced Astaxanthin Production in Escherichia coli via Morphology and Oxidative Stress Engineering. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:11703-11709. [PMID: 31578056 DOI: 10.1021/acs.jafc.9b05404] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Astaxanthin is a carotenoid of high commercial value because of its excellent antioxidative, anti-inflammatory, and anticancer properties. Here, we developed a novel strategy for improving the production of astaxanthin via morphology and oxidative stress engineering. First, we identified the morphology-/membrane- and oxidative stress-related genes, which should be knocked down, using the CRISPRi system. Deleting the morphology-/membrane-related genes (lpp and bamB) and the oxidative stress-related genes (uspE and yggE) generated longer and larger cells with higher reactive oxygen species (ROS) levels, thus enhancing the production of astaxanthin and decreasing cell growth. To not only improve cell growth but also obtain longer and larger cells with higher ROS levels, a complementary expression system using a temperature-sensitive plasmid was established. Complementarily expressing the morphology-/membrane-related genes (lpp and bamB) and the oxidative stress-related genes (uspE and yggE) further improved the production of astaxanthin to 11.92 mg/g dry cell weight in shake flask cultures.
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Affiliation(s)
- Qian Lu
- Institute of Synthetic Biology, Biomedical Center, Guangdong Province Key Laboratory of Improved Variety Reproduction in Aquatic Economic Animals and South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, School of Life Sciences , Sun Yat-sen University , Guangzhou 510275 , China
| | - Jian-Zhong Liu
- Institute of Synthetic Biology, Biomedical Center, Guangdong Province Key Laboratory of Improved Variety Reproduction in Aquatic Economic Animals and South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, School of Life Sciences , Sun Yat-sen University , Guangzhou 510275 , China
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Enhancement of Astaxanthin Biosynthesis in Oleaginous Yeast Yarrowia lipolytica via Microalgal Pathway. Microorganisms 2019; 7:microorganisms7100472. [PMID: 31635020 PMCID: PMC6843682 DOI: 10.3390/microorganisms7100472] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 10/16/2019] [Indexed: 12/05/2022] Open
Abstract
Astaxanthin is a high-value red pigment and antioxidant used by pharmaceutical, cosmetics, and food industries. The astaxanthin produced chemically is costly and is not approved for human consumption due to the presence of by-products. The astaxanthin production by natural microalgae requires large open areas and specialized equipment, the process takes a long time, and results in low titers. Recombinant microbial cell factories can be engineered to produce astaxanthin by fermentation in standard equipment. In this work, an oleaginous yeast Yarrowia lipolytica was engineered to produce astaxanthin at high titers in submerged fermentation. First, a platform strain was created with an optimised pathway towards β-carotene. The platform strain produced 331 ± 66 mg/L of β-carotene in small-scale cultivation, with the cellular content of 2.25% of dry cell weight. Next, the genes encoding β-ketolase and β-hydroxylase of bacterial (Paracoccus sp. and Pantoea ananatis) and algal (Haematococcus pluvialis) origins were introduced into the platform strain in different copy numbers. The resulting strains were screened for astaxanthin production, and the best strain, containing algal β-ketolase and β-hydroxylase, resulted in astaxanthin titer of 44 ± 1 mg/L. The same strain was cultivated in controlled bioreactors, and a titer of 285 ± 19 mg/L of astaxanthin was obtained after seven days of fermentation on complex medium with glucose. Our study shows the potential of Y. lipolytica as the cell factory for astaxanthin production.
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Fang N, Wang C, Liu X, Zhao X, Liu Y, Liu X, Du Y, Zhang Z, Zhang H. De novo synthesis of astaxanthin: From organisms to genes. Trends Food Sci Technol 2019. [DOI: 10.1016/j.tifs.2019.08.016] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Wu Y, Yan P, Liu X, Wang Z, Tang YJ, Chen T, Zhao X. Combinatorial expression of different β-carotene hydroxylases and ketolases in Escherichia coli for increased astaxanthin production. J Ind Microbiol Biotechnol 2019; 46:1505-1516. [PMID: 31297712 DOI: 10.1007/s10295-019-02214-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 07/04/2019] [Indexed: 01/10/2023]
Abstract
In natural produced bacteria, β-carotene hydroxylase (CrtZ) and β-carotene ketolase (CrtW) convert β-carotene into astaxanthin. To increase astaxanthin production in heterologous strain, simple and effective strategies based on the co-expression of CrtZ and CrtW were applied in E. coli. First, nine artificial operons containing crtZ and crtW genes from different sources were constructed and, respectively, introduced into E. coli ZF237T, a β-carotene producing host. Among the nine resulting strains, five accumulated detectable amounts of astaxanthin ranging from 0.49 to 8.07 mg/L. Subsequently, the protein fusion CrtZ to CrtW using optimized peptide linkers further increased the astaxanthin production. Strains expressing fusion proteins with CrtZ rather than CrtW attached to the N-terminus accumulated much more astaxanthin. The astaxanthin production of the best strain ZF237T/CrtZAs-(GS)1-WBs was 127.6% and 40.2% higher than that of strains ZF237T/crtZAsWBs and ZF237T/crtZBsWPs, respectively. The strategies depicted here also will be useful for the heterologous production of other natural products.
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Affiliation(s)
- Yuanqing Wu
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China
| | - Panpan Yan
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China
| | - Xuewei Liu
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China
| | - Zhiwen Wang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China
| | - Ya-Jie Tang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China.,Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Hubei University of Technology, Wuhan, 430068, People's Republic of China
| | - Tao Chen
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.
| | - Xueming Zhao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China
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55
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Moser S, Pichler H. Identifying and engineering the ideal microbial terpenoid production host. Appl Microbiol Biotechnol 2019; 103:5501-5516. [PMID: 31129740 PMCID: PMC6597603 DOI: 10.1007/s00253-019-09892-y] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 05/03/2019] [Accepted: 05/06/2019] [Indexed: 12/11/2022]
Abstract
More than 70,000 different terpenoid structures are known so far; many of them offer highly interesting applications as pharmaceuticals, flavors and fragrances, or biofuels. Extraction of these compounds from their natural sources or chemical synthesis is—in many cases—technically challenging with low or moderate yields while wasting valuable resources. Microbial production of terpenoids offers a sustainable and environment-friendly alternative starting from simple carbon sources and, frequently, safeguards high product specificity. Here, we provide an overview on employing recombinant bacteria and yeasts for heterologous de novo production of terpenoids. Currently, Escherichia coli and Saccharomyces cerevisiae are the two best-established production hosts for terpenoids. An increasing number of studies have been successful in engineering alternative microorganisms for terpenoid biosynthesis, which we intend to highlight in this review. Moreover, we discuss the specific engineering challenges as well as recent advances for microbial production of different classes of terpenoids. Rationalizing the current stages of development for different terpenoid production hosts as well as future prospects shall provide a valuable decision basis for the selection and engineering of the cell factory(ies) for industrial production of terpenoid target molecules.
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Affiliation(s)
- Sandra Moser
- Austrian Centre of Industrial Biotechnology (acib GmbH), Petersgasse 14, 8010, Graz, Austria
- Institute of Molecular Biotechnology, NAWI Graz, BioTechMed Graz, Graz University of Technology, Petersgasse 14/2, 8010, Graz, Austria
| | - Harald Pichler
- Austrian Centre of Industrial Biotechnology (acib GmbH), Petersgasse 14, 8010, Graz, Austria.
- Institute of Molecular Biotechnology, NAWI Graz, BioTechMed Graz, Graz University of Technology, Petersgasse 14/2, 8010, Graz, Austria.
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Duan G, Wu B, Qin H, Wang W, Tan Q, Dai Y, Qin Y, Tan F, Hu G, He M. Replacing water and nutrients for ethanol production by ARTP derived biogas slurry tolerant Zymomonas mobilis strain. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:124. [PMID: 31139254 PMCID: PMC6528197 DOI: 10.1186/s13068-019-1463-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 05/04/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Reducing fresh water consumption and nutrient addition will be an effective way to reduce the whole cost of bioethanol production. On the other hand, treatment of biogas slurry derived from anaerobic digestion (AD), in which a great amount of nutrients is still left, costs too much to remove these pollutants. It would be beneficial for both digestate valorization and ethanol production if biogas slurry is used for producing bioethanol. However, both hyperosmosis and potential biotoxic components of the biogas slurry can severely inhibit fermentation. RESULTS In this study, two rounds of atmospheric and room temperature plasma (ARTP) mutagenesis combined with adaptive laboratory evolution (ALE) were applied to improve the adaptability and genetic stability of Zymomonas mobilis in biogas slurry. Mutants D95 and S912 were identified. Growth of the mutants was remarkably improved in biogas slurry. The highest ethanol productivity reached 0.63 g/L/h which was 61.7% higher than ZM4 (0.39 g/L/h). Genomic re-sequencing results also revealed that single nucleic variations (SNVs) and Indels occurred in the mutants, which are likely related to inhibitor in biogas slurry and low pH tolerance. CONCLUSIONS Our study demonstrated that these mutant strains have great potential to produce ethanol using biogas slurry to replace fresh water and nutrients.
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Affiliation(s)
- Guowei Duan
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs) Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
- Graduate School of Chinese Academy of Agricultural Science, Beijing, 100081 People’s Republic of China
| | - Bo Wu
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs) Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
| | - Han Qin
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs) Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
| | - Weiting Wang
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs) Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
- Graduate School of Chinese Academy of Agricultural Science, Beijing, 100081 People’s Republic of China
| | - Qiong Tan
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs) Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
- Graduate School of Chinese Academy of Agricultural Science, Beijing, 100081 People’s Republic of China
| | - Yonghua Dai
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs) Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
- Graduate School of Chinese Academy of Agricultural Science, Beijing, 100081 People’s Republic of China
| | - Yao Qin
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs) Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
- College of Pharmacy and Biological Engineering, Chengdu University, Chengdu, 610041 People’s Republic of China
| | - Furong Tan
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs) Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
- Graduate School of Chinese Academy of Agricultural Science, Beijing, 100081 People’s Republic of China
| | - Guoquan Hu
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs) Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
- Graduate School of Chinese Academy of Agricultural Science, Beijing, 100081 People’s Republic of China
| | - Mingxiong He
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs) Biogas Institute of Ministry of Agriculture and Rural Affairs, Section 4-13, Renmin Rd. South, Chengdu, 610041 People’s Republic of China
- Graduate School of Chinese Academy of Agricultural Science, Beijing, 100081 People’s Republic of China
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57
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Wang C, Zhao S, Shao X, Park JB, Jeong SH, Park HJ, Kwak WJ, Wei G, Kim SW. Challenges and tackles in metabolic engineering for microbial production of carotenoids. Microb Cell Fact 2019; 18:55. [PMID: 30885243 PMCID: PMC6421696 DOI: 10.1186/s12934-019-1105-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 03/08/2019] [Indexed: 02/07/2023] Open
Abstract
Naturally occurring carotenoids have been isolated and used as colorants, antioxidants, nutrients, etc. in many fields. There is an ever-growing demand for carotenoids production. To comfort this, microbial production of carotenoids is an attractive alternative to current extraction from natural sources. This review summarizes the biosynthetic pathway of carotenoids and progresses in metabolic engineering of various microorganisms for carotenoid production. The advances in synthetic pathway and systems biology lead to many versatile engineering tools available to manipulate microorganisms. In this context, challenges and possible directions are also discussed to provide an insight of microbial engineering for improved production of carotenoids in the future.
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Affiliation(s)
- Chonglong Wang
- School of Biology and Basic Medical Sciences, Soochow University, 199 Renai Road, Suzhou, 215123, People's Republic of China.
| | - Shuli Zhao
- School of Biology and Basic Medical Sciences, Soochow University, 199 Renai Road, Suzhou, 215123, People's Republic of China
| | - Xixi Shao
- School of Biology and Basic Medical Sciences, Soochow University, 199 Renai Road, Suzhou, 215123, People's Republic of China
| | - Ji-Bin Park
- Division of Applied Life Science (BK21 Plus), PMBBRC, Gyeongsang National University, 501 Jinju-daero, Jinju, 52828, Republic of Korea
| | - Seong-Hee Jeong
- Division of Applied Life Science (BK21 Plus), PMBBRC, Gyeongsang National University, 501 Jinju-daero, Jinju, 52828, Republic of Korea
| | - Hyo-Jin Park
- Division of Applied Life Science (BK21 Plus), PMBBRC, Gyeongsang National University, 501 Jinju-daero, Jinju, 52828, Republic of Korea
| | - Won-Ju Kwak
- Division of Applied Life Science (BK21 Plus), PMBBRC, Gyeongsang National University, 501 Jinju-daero, Jinju, 52828, Republic of Korea
| | - Gongyuan Wei
- School of Biology and Basic Medical Sciences, Soochow University, 199 Renai Road, Suzhou, 215123, People's Republic of China
| | - Seon-Won Kim
- Division of Applied Life Science (BK21 Plus), PMBBRC, Gyeongsang National University, 501 Jinju-daero, Jinju, 52828, Republic of Korea.
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58
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Yuan SF, Alper HS. Metabolic engineering of microbial cell factories for production of nutraceuticals. Microb Cell Fact 2019; 18:46. [PMID: 30857533 PMCID: PMC6410520 DOI: 10.1186/s12934-019-1096-y] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 02/27/2019] [Indexed: 11/18/2022] Open
Abstract
Metabolic engineering allows for the rewiring of basic metabolism to overproduce both native and non-native metabolites. Among these biomolecules, nutraceuticals have received considerable interest due to their health-promoting or disease-preventing properties. Likewise, microbial engineering efforts to produce these value-added nutraceuticals overcome traditional limitations of low yield from extractions and complex chemical syntheses. This review covers current strategies of metabolic engineering employed for the production of a few key nutraceuticals with selecting polyunsaturated fatty acids, polyphenolic compounds, carotenoids and non-proteinogenic amino acids as exemplary molecules. We focus on the use of both mono-culture and co-culture strategies to produce these molecules of interest. In each of these cases, metabolic engineering efforts are enabling rapid production of these molecules.
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Affiliation(s)
- Shuo-Fu Yuan
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, USA
| | - Hal S Alper
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, USA.
- McKetta Department of Chemical Engineering, The University of Texas at Austin, 200 E Dean Keeton St. Stop C0400, Austin, TX, 78712, USA.
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Zhou P, Li M, Shen B, Yao Z, Bian Q, Ye L, Yu H. Directed Coevolution of β-Carotene Ketolase and Hydroxylase and Its Application in Temperature-Regulated Biosynthesis of Astaxanthin. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:1072-1080. [PMID: 30606005 DOI: 10.1021/acs.jafc.8b05003] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Because it is an outstanding antioxidant with wide applications, biotechnological production of astaxanthin has attracted increasing research interest. However, the astaxanthin titer achieved to date is still rather low, attributed to the poor efficiency of β-carotene ketolation and hydroxylation, as well as the adverse effect of astaxanthin accumulation on cell growth. To address these problems, we constructed an efficient astaxanthin-producing Saccharomyces cerevisiae strain by combining protein engineering and dynamic metabolic regulation. First, superior mutants of β-carotene ketolase and β-carotene hydroxylase were obtained by directed coevolution to accelerate the conversion of β-carotene to astaxanthin. Subsequently, the Gal4M9-based temperature-responsive regulation system was introduced to separate astaxanthin production from cell growth. Finally, 235 mg/L of (3 S,3' S)-astaxanthin was produced by two-stage, high-density fermentation. This study demonstrates the power of combining directed coevolution and temperature-responsive regulation in astaxanthin biosynthesis and may provide methodological reference for biotechnological production of other value-added chemicals.
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Affiliation(s)
- Pingping Zhou
- Institute of Bioengineering, College of Chemical and Biological Engineering , Zhejiang University , Hangzhou 310027 , P.R. China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety/Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, The Ministry of Education of China , Yangzhou University , Yangzhou 225009 , P.R. China
| | - Min Li
- Institute of Bioengineering, College of Chemical and Biological Engineering , Zhejiang University , Hangzhou 310027 , P.R. China
| | - Bin Shen
- Institute of Bioengineering, College of Chemical and Biological Engineering , Zhejiang University , Hangzhou 310027 , P.R. China
| | - Zhen Yao
- Institute of Bioengineering, College of Chemical and Biological Engineering , Zhejiang University , Hangzhou 310027 , P.R. China
| | - Qi Bian
- Institute of Bioengineering, College of Chemical and Biological Engineering , Zhejiang University , Hangzhou 310027 , P.R. China
| | - Lidan Ye
- Institute of Bioengineering, College of Chemical and Biological Engineering , Zhejiang University , Hangzhou 310027 , P.R. China
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education , Zhejiang University , Hangzhou 310027 , P.R. China
| | - Hongwei Yu
- Institute of Bioengineering, College of Chemical and Biological Engineering , Zhejiang University , Hangzhou 310027 , P.R. China
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education , Zhejiang University , Hangzhou 310027 , P.R. China
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60
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Wu B, Qin H, Yang Y, Duan G, Yang S, Xin F, Zhao C, Shao H, Wang Y, Zhu Q, Tan F, Hu G, He M. Engineered Zymomonas mobilis tolerant to acetic acid and low pH via multiplex atmospheric and room temperature plasma mutagenesis. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:10. [PMID: 30627218 PMCID: PMC6321654 DOI: 10.1186/s13068-018-1348-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 12/24/2018] [Indexed: 05/19/2023]
Abstract
BACKGROUND Cellulosic biofuels are sustainable compared to fossil fuels. However, inhibitors, such as acetic acid generated during lignocellulose pretreatment and hydrolysis, would significantly inhibit microbial fermentation efficiency. Microbial mutants able to tolerate high concentration of acetic acid are needed urgently to alleviate this inhibition. RESULTS Zymomonas mobilis mutants AQ8-1 and AC8-9 with enhanced tolerance against acetic acid were generated via a multiplex atmospheric and room temperature plasma (mARTP) mutagenesis. The growth and ethanol productivity of AQ8-1 and AC8-9 were both improved in the presence of 5.0-8.0 g/L acetic acid. Ethanol yield reached 84% of theoretical value in the presence of 8.0 g/L acetic acid (~ pH 4.0). Furthermore, a mutant tolerant to pH 3.5, named PH1-29, was generated via the third round of ARTP mutagenesis. PH1-29 showed enhanced growth and ethanol production under both sterilized/unsterilized conditions at pH 4.0 or 3.5. Intracellular NAD levels revealed that mARTP mutants could modulate NADH/NAD+ ratio to respond to acetic acid and low pH stresses. Moreover, genomic re-sequencing revealed that eleven single nucleic variations (SNVs) were likely related to acetic acid and low pH tolerance. Most SNVs were targeted in regions between genes ZMO0952 and ZMO0956, ZMO0152 and ZMO0153, and ZMO0373 and ZMO0374. CONCLUSIONS The multiplex mutagenesis strategy mARTP was efficient for enhancing the tolerance in Z. mobilis. The ARTP mutants generated in this study could serve as potential cellulosic ethanol producers.
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Affiliation(s)
- Bo Wu
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture), Biogas Institute of Ministry of Agriculture, Section 4-13, Renmin Rd. South, Chengdu, 610041 China
| | - Han Qin
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture), Biogas Institute of Ministry of Agriculture, Section 4-13, Renmin Rd. South, Chengdu, 610041 China
| | - Yiwei Yang
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture), Biogas Institute of Ministry of Agriculture, Section 4-13, Renmin Rd. South, Chengdu, 610041 China
| | - Guowei Duan
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture), Biogas Institute of Ministry of Agriculture, Section 4-13, Renmin Rd. South, Chengdu, 610041 China
| | - Shihui Yang
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Environmental Microbial Technology Center of Hubei Province, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan, 430062 China
| | - Fengxue Xin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 Puzhu Rd, Pukou District, Nanjing, 211816 China
| | - Chunyan Zhao
- College of Life Science, Sichuan Normal University, Section 2-1819, Chenglong Avenue, Chengdu, 610101 China
| | - Huanhuan Shao
- College of Life Science, Sichuan Normal University, Section 2-1819, Chenglong Avenue, Chengdu, 610101 China
| | - Yanwei Wang
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture), Biogas Institute of Ministry of Agriculture, Section 4-13, Renmin Rd. South, Chengdu, 610041 China
| | - Qili Zhu
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture), Biogas Institute of Ministry of Agriculture, Section 4-13, Renmin Rd. South, Chengdu, 610041 China
| | - Furong Tan
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture), Biogas Institute of Ministry of Agriculture, Section 4-13, Renmin Rd. South, Chengdu, 610041 China
| | - Guoquan Hu
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture), Biogas Institute of Ministry of Agriculture, Section 4-13, Renmin Rd. South, Chengdu, 610041 China
| | - Mingxiong He
- Biomass Energy Technology Research Centre, Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture), Biogas Institute of Ministry of Agriculture, Section 4-13, Renmin Rd. South, Chengdu, 610041 China
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Huang L, Gao B, Wu M, Wang F, Zhang C. Comparative transcriptome analysis of a long-time span two-step culture process reveals a potential mechanism for astaxanthin and biomass hyper-accumulation in Haematococcus pluvialis JNU35. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:18. [PMID: 30705704 PMCID: PMC6348685 DOI: 10.1186/s13068-019-1355-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Accepted: 01/09/2019] [Indexed: 05/04/2023]
Abstract
BACKGROUND Among all organisms tested, Haematococcus pluvialis can accumulate the highest levels of natural astaxanthin. Nitrogen starvation and high irradiance promote the accumulation of starch, lipid, and astaxanthin in H. pluvialis, yet their cell division is significantly retarded. Accordingly, adaptive regulatory mechanisms are very important and necessary to optimize the cultivation conditions enabling an increase in biomass; as well as promoting astaxanthin accumulation by H. pluvialis. To clarify the intrinsic mechanism of high-level astaxanthin and biomass accumulation in the newly isolated strain, H. pluvialis JNU35, nitrogen-sufficiency and nitrogen-depletion conditions were employed. Time-resolved comparative transcriptome analysis was also conducted by crossing the two-step culture process. RESULTS In the present study, we report the overall growth and physiological, biochemical, and transcriptomic characteristics of H. pluvialis JNU35 in response to nitrogen variation. From eight sampling time-points (2 days, 4 days, 8 days, 10 days, 12 days, 14 days, 16 days, and 20 days), 25,480 differentially expressed genes were found. These genes included the significantly responsive unigenes associated with photosynthesis, astaxanthin biosynthesis, and nitrogen metabolic pathways. The expressions of all key and rate-limiting genes involved in astaxanthin synthesis were significantly upregulated. The photosynthetic pathway was found to be attenuated, whereas the ferredoxin gene was upregulated, which might activate the cyclic electron-transport chain as compensation. Moreover, the expressions of genes related to nitrogen transport and assimilation were upregulated. The expressions of genes in the proteasome pathway were also upregulated. In contrast, the chloroplasts and nonessential proteins were gradually degraded, activating the specific ornithine-urea cycle pathway. These changes may promote the sustained accumulation of astaxanthin and biomass. CONCLUSIONS To the best of our knowledge, this paper is the first to investigate the long-term differences of gene expression from two-step culture process in the astaxanthin producer, H. pluvialis JNU35. According to our results, β-carotene ketolase (bkt1 and bkt2) serves as the key enzyme regulating astaxanthin accumulation in H. pluvialis JNU35. The cyclic electron-transport chain and novel nitrogen metabolic process were used adaptively as the regulatory mechanism compensating for different levels of stress. The in-depth study of these metabolic pathways and related key genes can reveal the underlying relationship between cell growth and astaxanthin accumulation in H. pluvialis JNU35.
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Affiliation(s)
- Luodong Huang
- Department of Ecology, Institute of Hydrobiology, College of Life Science and Technology, Jinan University, No.601 Huangpu Road, Tianhe District, Guangzhou, 510632 Guangdong People’s Republic of China
| | - Baoyan Gao
- Department of Ecology, Institute of Hydrobiology, College of Life Science and Technology, Jinan University, No.601 Huangpu Road, Tianhe District, Guangzhou, 510632 Guangdong People’s Republic of China
| | - Manman Wu
- Department of Ecology, Institute of Hydrobiology, College of Life Science and Technology, Jinan University, No.601 Huangpu Road, Tianhe District, Guangzhou, 510632 Guangdong People’s Republic of China
| | - Feifei Wang
- Department of Ecology, Institute of Hydrobiology, College of Life Science and Technology, Jinan University, No.601 Huangpu Road, Tianhe District, Guangzhou, 510632 Guangdong People’s Republic of China
| | - Chengwu Zhang
- Department of Ecology, Institute of Hydrobiology, College of Life Science and Technology, Jinan University, No.601 Huangpu Road, Tianhe District, Guangzhou, 510632 Guangdong People’s Republic of China
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