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Chen YY, Huang JC, Wu CY, Yu SQ, Wang YT, Ye C, Shi TQ, Huang H. A comprehensive review on the recent advances for 5-aminolevulinic acid production by the engineered bacteria. Crit Rev Biotechnol 2024:1-16. [PMID: 38705840 DOI: 10.1080/07388551.2024.2336532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Accepted: 03/13/2024] [Indexed: 05/07/2024]
Abstract
5-Aminolevulinic acid (5-ALA) is a non-proteinogenic amino acid essential for synthesizing tetrapyrrole compounds, including heme, chlorophyll, cytochrome, and vitamin B12. As a plant growth regulator, 5-ALA is extensively used in agriculture to enhance crop yield and quality. The complexity and low yield of chemical synthesis methods have led to significant interest in the microbial synthesis of 5-ALA. Advanced strategies, including the: enhancement of precursor and cofactor supply, compartmentalization of key enzymes, product transporters engineering, by-product formation reduction, and biosensor-based dynamic regulation, have been implemented in bacteria for 5-ALA production, significantly advancing its industrialization. This article offers a comprehensive review of recent developments in 5-ALA production using engineered bacteria and presents new insights to propel the field forward.
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Affiliation(s)
- Ying-Ying Chen
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Jia-Cong Huang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Cai-Yun Wu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Shi-Qin Yu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
- Science Center for Future Foods, Jiangnan University, Wuxi, China
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, China
| | - Yue-Tong Wang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Chao Ye
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Tian-Qiong Shi
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - He Huang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
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Zeng M, Wu H, Han Z, Du Z, Yu X, Luo W. Metabolic Engineering of Escherichia coli for Production of 2,5-Dimethylpyrazine. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:4267-4276. [PMID: 38369722 DOI: 10.1021/acs.jafc.3c08481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
2,5-Dimethylpyrazine (2,5-DMP) is a high-value-added alkylpyrazine compound with important applications in both the food and pharmaceutical fields. In response to the increasing consumer preference for natural products over chemically synthesized ones, efforts have been made to develop efficient microbial cell factories for the production of 2,5-DMP. However, the previously reported recombinant strains have exhibited low yields and relied on expensive antibiotics and inducers. In this study, we employed metabolic engineering strategies to develop an Escherichia coli strain capable of producing 2,5-DMP at high levels without the need for inducers or antibiotics. Initially, the biosynthesis pathway of 2,5-DMP was constructed that realized 2,5-DMP production from glucose. Subsequently, efforts focused on enhancing 2,5-DMP production by improving the availability of the cofactor NAD+ and precursor l-threonine. Additionally, the supply and conversion of l-threonine were balanced by optimizing the copy number of the key gene tdh on the chromosome and by modifying the l-threonine transport system. The final engineering strain D19 produced 3.1 g/L of 2,5-DMP, which is the highest titer for fermentative production of 2,5-DMP using glucose as the carbon source up to date. The strategies used in this study lay a good foundation for the production of 2,5-DMP on a large scale.
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Affiliation(s)
- Mingxi Zeng
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Hui Wu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200231, China
| | - Zhenlin Han
- Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Zhiyan Du
- Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Xiaobin Yu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Wei Luo
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China
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Liu Z, Cai M, Zhou S, You J, Zhao Z, Liu Z, Xu M, Rao Z. High-efficient production of L-homoserine in Escherichia coli through engineering synthetic pathway combined with regulating cell division. BIORESOURCE TECHNOLOGY 2023; 389:129828. [PMID: 37806363 DOI: 10.1016/j.biortech.2023.129828] [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: 08/15/2023] [Revised: 10/03/2023] [Accepted: 10/03/2023] [Indexed: 10/10/2023]
Abstract
L-Homoserine is an important amino acid as a precursor in synthesizing many valuable products. However, the low productivity caused by slow L-homoserine production during active cell growth in fermentation hinders its potential applications. In this study, strategies of engineering the synthetic pathway combined with regulating cell division were employed in an L-homoserine-producing Escherichia coli strain for efficiently biomanufacturing L-homoserine. First, the flux-control genes in the L-homoserine degradation pathway were omitted to redistribute carbon flux. To drive more carbon flux into L-homoserine production, the phosphoenolpyruvate-pyruvate-oxaloacetate loop was redrawn. Subsequently, the cell division was engineered by using the self-regulated promoters to coordinate cell growth and L-homoserine production. The ultimate strain HOM23 produced 101.31 g/L L-homoserine with a productivity of 1.91 g/L/h, which presented the highest L-homoserine titer and productivity to date from plasmid-free strains. The strategies used in this study could be applied to constructing cell factories for producing other L-aspartate derivatives.
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Affiliation(s)
- Zhifei Liu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, Jiangsu 214200, China
| | - Mengmeng Cai
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, Jiangsu 214200, China
| | - Siquan Zhou
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, Jiangsu 214200, China
| | - Jiajia You
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, Jiangsu 214200, China
| | - Zhenqiang Zhao
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, Jiangsu 214200, China
| | - Zuyi Liu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, Jiangsu 214200, China
| | - Meijuan Xu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, Jiangsu 214200, China
| | - Zhiming Rao
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, Jiangsu 214200, China.
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Cai M, Liu Z, Zhao Z, Wu H, Xu M, Rao Z. Microbial production of L-methionine and its precursors using systems metabolic engineering. Biotechnol Adv 2023; 69:108260. [PMID: 37739275 DOI: 10.1016/j.biotechadv.2023.108260] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 08/11/2023] [Accepted: 09/18/2023] [Indexed: 09/24/2023]
Abstract
L-methionine is an essential amino acid with versatile applications in food, feed, cosmetics and pharmaceuticals. At present, the production of L-methionine mainly relies on chemical synthesis, which conflicts with the concern over serious environmental problems and sustainable development goals. In recent years, microbial production of natural products has been amply rewarded with the emergence and rapid development of system metabolic engineering. However, efficient L-methionine production by microbial fermentation remains a great challenge due to its complicated biosynthetic pathway and strict regulatory mechanism. Additionally, the engineered production of L-methionine precursors, L-homoserine, O-succinyl-L-homoserine (OSH) and O-acetyl-L-homoserine (OAH), has also received widespread attention because they can be catalyzed to L-methionine via a high-efficiently enzymatic reaction in vitro, which is also a promising alternative to chemical route. This review provides a comprehensive overview on the recent advances in the microbial production of L-methionine and its precursors, highlighting the challenges and potential solutions for developing L-methionine microbial cell factories from the perspective of systems metabolic engineering, aiming to offer guidance for future engineering.
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Affiliation(s)
- Mengmeng Cai
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China
| | - Zhifei Liu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China
| | - Zhenqiang Zhao
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China
| | - Hongxuan Wu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China
| | - Meijuan Xu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China
| | - Zhiming Rao
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China.
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Wei Z, Zhao D, Wang J, Li J, Xu N, Ding C, Liu J, Li S, Zhang C, Bi C, Zhang X. Targeted C-to-T and A-to-G dual mutagenesis system for RhtA transporter in vivo evolution. Appl Environ Microbiol 2023; 89:e0075223. [PMID: 37728922 PMCID: PMC10617597 DOI: 10.1128/aem.00752-23] [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: 05/11/2023] [Accepted: 07/24/2023] [Indexed: 09/22/2023] Open
Abstract
T7 RNA polymerase (T7RNAP) has been fused with cytosine or adenine deaminase individually, enabling in vivo C-to-T or A-to-G transitions on DNA sequence downstream of T7 promoter, and greatly accelerated directed protein evolution. However, its base conversion type is limited. In this study, we created a dual-functional system for simultaneous C-to-T and A-to-G in vivo mutagenesis, called T7-DualMuta, by fusing T7RNAP with both cytidine deaminase (PmCDA1) and a highly active adenine deaminase (TadA-8e). The C-to-T and A-to-G mutagenesis frequencies of T7-DualMuta were 4.02 × 10-3 and 1.20 × 10-2, respectively, with 24 h culturing and distributed mutations evenly across the target gene. The T7-DualMuta system was used to in vivo directed evolution of L-homoserine transporter RhtA, resulting in efficient variants that carried the four types of base conversions by T7-DualMuta. The evolved variants greatly increased the host growth rates at L-homoserine concentrations of 8 g/L, which was not previously achieved, and demonstrated the great in vivo evolution capacity. The novel molecular device T7-DualMuta efficiently provides both C/G-to-T/A and A/T-to-G/C mutagenesis on target regions, making it useful for various applications and research in Enzymology and Synthetic Biology studies. It also represents an important expansion of the base editing toolbox.ImportanceA T7-DualMuta system for simultaneous C-to-T and A-to-G in vivo mutagenesis was created. The mutagenesis frequency was 4.02 × 107 fold higher than the spontaneous mutation, which was reported to be approximately 10-10 bases per nucleotide per generation. This mutant system can be utilized for various applications and research in Enzymology and Synthetic Biology studies.
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Affiliation(s)
- Zhandong Wei
- School of Biological Engineering, Dalian Polytechnic University, Dalian, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Dongdong Zhao
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Jie Wang
- School of Biological Engineering, Dalian Polytechnic University, Dalian, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Ju Li
- College of Life Science, Tianjin Normal University, Tianjin, China
| | - Ning Xu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Chao Ding
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Jun Liu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Siwei Li
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Chunzhi Zhang
- School of Biological Engineering, Dalian Polytechnic University, Dalian, China
| | - Changhao Bi
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Xueli Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, China
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Tang M, Pan X, Yang T, You J, Zhu R, Yang T, Zhang X, Xu M, Rao Z. Multidimensional engineering of Escherichia coli for efficient synthesis of L-tryptophan. BIORESOURCE TECHNOLOGY 2023; 386:129475. [PMID: 37451510 DOI: 10.1016/j.biortech.2023.129475] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 07/05/2023] [Accepted: 07/07/2023] [Indexed: 07/18/2023]
Abstract
Development of microbial cell factory for L-tryptophan (L-trp) production has received widespread attention but still requires extensive efforts due to weak metabolic flux distribution and low yield. Here, the riboswitch-based high-throughput screening (HTS) platform was established to construct a powerful L-trp-producing chassis cell. To facilitate L-trp biosynthesis, gene expression was regulated by promoter and N-terminal coding sequences (NCS) engineering. Modules of degradation, transport and by-product synthesis related to L-trp production were also fine-tuned. Next, a novel transcription factor YihL was excavated to negatively regulate L-trp biosynthesis. Self-regulated promoter-mediated dynamic regulation of branch pathways was performed and cofactor supply was improved for further L-trp biosynthesis. Finally, without extra addition, the yield of strain Trp30 reached 42.5 g/L and 0.178 g/g glucose after 48 h of cultivation in 5-L bioreactor. Overall, strategies described here worked up a promising method combining HTS and multidimensional regulation for developing cell factories for products in interest.
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Affiliation(s)
- Mi Tang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China
| | - Xuewei Pan
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China
| | - Tianjin Yang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China
| | - Jiajia You
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China
| | - Rongshuai Zhu
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China
| | - Taowei Yang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China
| | - Xian Zhang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China
| | - Meijuan Xu
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China
| | - Zhiming Rao
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China.
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Du H, Qi Y, Qiao J, Li L, Wei L, Xu N, Shao L, Liu J. Transcription factor OxyR regulates sulfane sulfur removal and L-cysteine biosynthesis in Corynebacterium glutamicum. Appl Environ Microbiol 2023; 89:e0090423. [PMID: 37768042 PMCID: PMC10537588 DOI: 10.1128/aem.00904-23] [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: 05/31/2023] [Accepted: 07/09/2023] [Indexed: 09/29/2023] Open
Abstract
Sulfane sulfur, a collective term for hydrogen polysulfide and organic persulfide, often damages cells at high concentrations. Cells can regulate intracellular sulfane sulfur levels through specific mechanisms, but these mechanisms are unclear in Corynebacterium glutamicum. OxyR is a transcription factor capable of sensing oxidative stress and is also responsive to sulfane sulfur. In this study, we found that OxyR functioned directly in regulating sulfane sulfur in C. glutamicum. OxyR binds to the promoter of katA and nrdH and regulates its expression, as revealed via in vitro electrophoretic mobility shift assay analysis, real-time quantitative PCR, and reporting systems. Overexpression of katA and nrdH reduced intracellular sulfane sulfur levels by over 30% and 20% in C. glutamicum, respectively. RNA-sequencing analysis showed that the lack of OxyR downregulated the expression of sulfur assimilation pathway genes and/or sulfur transcription factors, which may reduce the rate of sulfur assimilation. In addition, OxyR also affected the biosynthesis of L-cysteine in C. glutamicum. OxyR overexpression strain Cg-2 accumulated 183 mg/L of L-cysteine, increased by approximately 30% compared with the control (142 mg/L). In summary, OxyR not only regulated sulfane sulfur levels by controlling the expression of katA and nrdH in C. glutamicum but also facilitated the sulfur assimilation and L-cysteine synthesis pathways, providing a potential target for constructing robust cell factories of sulfur-containing amino acids and their derivatives. IMPORTANCE C. glutamicum is an important industrial microorganism used to produce various amino acids. In the production of sulfur-containing amino acids, cells inevitably accumulate a large amount of sulfane sulfur. However, few studies have focused on sulfane sulfur removal in C. glutamicum. In this study, we not only revealed the regulatory mechanism of OxyR on intracellular sulfane sulfur removal but also explored the effects of OxyR on the sulfur assimilation and L-cysteine synthesis pathways in C. glutamicum. This is the first study on the removal of sulfane sulfur in C. glutamicum. These results contribute to the understanding of sulfur regulatory mechanisms and may aid in the future optimization of C. glutamicum for biosynthesis of sulfur-containing amino acids.
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Affiliation(s)
- Huanmin Du
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yuting Qi
- Department of Microbiology and Biotechnology, College of Life Sciences, Northeast Agricultural University, Harbin, China
| | - Jinfang Qiao
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Lingcong Li
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Liang Wei
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Ning Xu
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Li Shao
- Department of Microbiology and Biotechnology, College of Life Sciences, Northeast Agricultural University, Harbin, China
| | - Jun Liu
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
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Du H, Qi Y, Qiao J, Li L, Xu N, Shao L, Wei L, Liu J. Balancing Redox Homeostasis to Improve l-Cysteine Production in Corynebacterium glutamicum. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:13848-13856. [PMID: 37669547 DOI: 10.1021/acs.jafc.3c03828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
l-Cysteine is a valuable sulfur-containing amino acid with applications across a wide range of fields. Recently, microbial fermentation has emerged as a method to produce l-cysteine. However, cellular redox stress from high levels of l-cysteine is a bottleneck for achieving efficient production. In this study, we aimed to facilitate l-cysteine biosynthesis by modulating cellular redox homeostasis through the introduction of the natural antioxidant astaxanthin in Corynebacterium glutamicum. To achieve this, we first introduced an exogenous astaxanthin synthesis module in C. glutamicum. Then, an l-cysteine-dependent autonomous bifunctional genetic switch was developed to dynamically regulate the l-cysteine and astaxanthin biosynthesis pathway to maintain cellular redox homeostasis. This regulation system achieved high biosynthesis of astaxanthin, which significantly facilitated l-cysteine production. Finally, engineered strain Cg-10 produced 8.45 g/L l-cysteine and 95 mg/L astaxanthin in a 5 L bioreactor, both of which are the highest reported levels in C. glutamicum.
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Affiliation(s)
- Huanmin Du
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West seventh Avenue, Tianjin Airport Economic Area, Tianjin 300308, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuting Qi
- Department of Microbiology and Biotechnology, College of Life Sciences, Northeast Agricultural University, No. 600 Changjiang Road, Xiangfang District, Harbin 150030, China
| | - Jinfang Qiao
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Lingcong Li
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West seventh Avenue, Tianjin Airport Economic Area, Tianjin 300308, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ning Xu
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West seventh Avenue, Tianjin Airport Economic Area, Tianjin 300308, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Li Shao
- Department of Microbiology and Biotechnology, College of Life Sciences, Northeast Agricultural University, No. 600 Changjiang Road, Xiangfang District, Harbin 150030, China
| | - Liang Wei
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West seventh Avenue, Tianjin Airport Economic Area, Tianjin 300308, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Jun Liu
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West seventh Avenue, Tianjin Airport Economic Area, Tianjin 300308, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
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9
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Ding X, Yang W, Du X, Chen N, Xu Q, Wei M, Zhang C. High-level and -yield production of L-leucine in engineered Escherichia coli by multistep metabolic engineering. Metab Eng 2023; 78:128-136. [PMID: 37286072 DOI: 10.1016/j.ymben.2023.06.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 05/19/2023] [Accepted: 06/04/2023] [Indexed: 06/09/2023]
Abstract
L-leucine is an essential amino acid widely used in food and pharmaceutical industries. However, the relatively low production efficiency limits its large-scale application. In this study, we rationally developed an efficient L-leucine-producing Escherichia coli strain. Initially, the L-leucine synthesis pathway was enhanced by overexpressing feedback-resistant 2-isopropylmalate synthase and acetohydroxy acid synthase both derived from Corynebacterium glutamicum, along with two other native enzymes. Next, the pyruvate and acetyl-CoA pools were enriched by deleting competitive pathways, employing the nonoxidative glycolysis pathway, and dynamically modulating the citrate synthase activity, which significantly promoted the L-leucine production and yield to 40.69 g/L and 0.30 g/g glucose, respectively. Then, the redox flux was improved by substituting the native NADPH-dependent acetohydroxy acid isomeroreductase, branched chain amino acid transaminase, and glutamate dehydrogenase with their NADH-dependent equivalents. Finally, L-leucine efflux was accelerated by precise overexpression of the exporter and deletion of the transporter. Under fed-batch conditions, the final strain LXH-21 produced 63.29 g/L of L-leucine, with a yield and productivity of 0.37 g/g glucose and 2.64 g/(L h), respectively. To our knowledge, this study achieved the highest production efficiency of L-leucine to date. The strategies presented here will be useful for engineering E. coli strains for producing L-leucine and related products on an industrial scale.
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Affiliation(s)
- Xiaohu Ding
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science and Technology, Tianjin, 300457, China; College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Wenjun Yang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Xiaobin Du
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Ning Chen
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science and Technology, Tianjin, 300457, China; College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Qingyang Xu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science and Technology, Tianjin, 300457, China; College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Minhua Wei
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.
| | - Chenglin Zhang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science and Technology, Tianjin, 300457, China; College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.
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10
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Shen ZY, Wang YF, Wang LJ, Wang Y, Liu ZQ, Zheng YG. Thorough research and modification of one-carbon units cycle for improving L-methionine production in Escherichia coli. 3 Biotech 2023; 13:203. [PMID: 37220602 PMCID: PMC10199968 DOI: 10.1007/s13205-023-03625-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 05/09/2023] [Indexed: 05/25/2023] Open
Abstract
Methionine is the only one of the essential amino acids that contain sulfur, widely used as a feed additive in agriculture. In this study, the availability of 5-methyl-tetrahydrofolate was confirmed as the main limitation in the complex multibranched biosynthetic pathway of L-methionine. The cycle of one-carbon units was thoroughly investigated and modified to supply 5-methyl-tetrahydrofolate for L-methionine production, such as enhancing the supply of precursor, expediting the conversion rate of the cycle, introducing exogenous serine hydroxymethyltransferase and increasing pool size of one-carbon units carrier. The final strain MYA/pAmFA-4 was able to produce 20.89 g/L L-methionine by fed-batch fermentation, which was the highest titer reported in the literatures. This study is instructive for other metabolites biosynthesized needing one-carbon units or having a complex multibranched biosynthetic pathway. Supplementary Information The online version contains supplementary material available at 10.1007/s13205-023-03625-9.
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Affiliation(s)
- Zhen-Yang Shen
- National and Local Joint Engineering Research Center for Biomanufacturing of Choral Chemicals, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
| | - Yi-Feng Wang
- National and Local Joint Engineering Research Center for Biomanufacturing of Choral Chemicals, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
| | - Li-Juan Wang
- National and Local Joint Engineering Research Center for Biomanufacturing of Choral Chemicals, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
| | - Ying Wang
- National and Local Joint Engineering Research Center for Biomanufacturing of Choral Chemicals, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
| | - Zhi-Qiang Liu
- National and Local Joint Engineering Research Center for Biomanufacturing of Choral Chemicals, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
| | - Yu-Guo Zheng
- National and Local Joint Engineering Research Center for Biomanufacturing of Choral Chemicals, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 People’s Republic of China
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11
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Niu K, Fu Q, Mei ZL, Ge LR, Guan AQ, Liu ZQ, Zheng YG. High-Level Production of l-Methionine by Dynamic Deregulation of Metabolism with Engineered Nonauxotroph Escherichia coli. ACS Synth Biol 2023; 12:492-501. [PMID: 36701126 DOI: 10.1021/acssynbio.2c00481] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
l-Methionine is the only sulfur-containing amino acid among the essential amino acids, and it is mainly produced by the chemical method in industry so far. The fermentation production of l-methionine by genetically engineered strains is an attractive alternative. Due to the complex metabolic mechanism and multilevel regulation of the synthesis pathway in the organism, the fermentation production of l-methionine by genetically engineered strains was still not satisfied. In this study, the biosynthesis pathway of l-methionine was regulated based on the previous studies. As the competitive pathway and an essential amino acid for cell growth, the biosynthesis pathway of l-lysine was first repaired by complementation of the lysA gene in situ on the genome and then replaced the in situ promoter with the dynamically regulated promoter PfliA to construct a nonauxotroph strain. In addition, the central metabolic pathway and l-cysteine catabolism pathway were further modified to promote the cell growth and enhance the l-methionine production. Finally, the l-methionine fermentation yield in a 5 L bioreactor reached 17.74 g/L without adding exogenous amino acids. These strategies can effectively balance the contradiction between cell growth and l-methionine production and alleviate the complexity of fermentation operation and the cost with auxotroph strains, which provide a reference for the industrial production of l-methionine by microbial fermentation.
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Affiliation(s)
- Kun Niu
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Qiang Fu
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Zi-Long Mei
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Li-Rong Ge
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - An-Qi Guan
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Zhi-Qiang Liu
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Yu-Guo Zheng
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
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12
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Sun BY, Wang FQ, Zhao J, Tao XY, Liu M, Wei DZ. Engineering Escherichia coli for l-homoserine production. J Basic Microbiol 2023; 63:168-178. [PMID: 36284486 DOI: 10.1002/jobm.202200488] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 09/13/2022] [Accepted: 10/01/2022] [Indexed: 02/03/2023]
Abstract
l-homoserine, a nonprotein amino acid, is used to synthesize many active substances in the industry. Here, to develop a robust l-homoserine-producing strain, Escherichia coli W3110 was used as a chassis to be engineered. Based on a previous construct with blocked competing routes for l-homoserine synthesis, five genes were overexpressed by promoter replacement strategy to increase the l-homoserine production, including enhancement of precursors for l-homoserine synthesis (ppc, thrA, and asd), reinforcement of the NADPH supply (pntAB) and efflux transporters (rhtA) to improve the l-homoserine production. However, the plasmid losing was to blame for the wildly fluctuating fermentation performance of engineered strains, ranging between 2.1 and 6.2 g/L. Then, a hok/sok toxin/antitoxin system was introduced into the free plasmid expression cassette to maintain the genetic stability of the episomal plasmid; consequently, the plasmid-losing rate sharply decreased, resulting in the engineered strain SHL17, which exhibited excellent stability in l-homoserine production, with 6.3 g/L in shake flasks and 44.4 g/L in a 5-L fermenter without antibiotic addition. This work verified the effective use of the hok/sok toxin/antitoxin system combined with promoter engineering to improve the genetic stability of E. coli episomal plasmids without antibiotics.
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Affiliation(s)
- Bing-Yao Sun
- State Key Lab of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Feng-Qing Wang
- State Key Lab of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Jian Zhao
- State Key Lab of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Xin-Yi Tao
- State Key Lab of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Min Liu
- State Key Lab of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Dong-Zhi Wei
- State Key Lab of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai, China
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13
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Li N, Li L, Yu S, Zhou J. Dual-channel glycolysis balances cofactor supply for l-homoserine biosynthesis in Corynebacterium glutamicum. BIORESOURCE TECHNOLOGY 2023; 369:128473. [PMID: 36509305 DOI: 10.1016/j.biortech.2022.128473] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
l-Homoserine is an important platform compound that is widely used to produce many valuable bio-based products, but production of l-homoserine in Corynebacterium glutamicum remains low. In this study, an efficient l-homoserine-producing strain was constructed. Native pentose phosphate pathway (PPP) was enhanced and heterologous Entner-Doudoroff (ED) pathway was carefully introduced into l-homoserine-producing strain, which increased the l-homoserine titer. Coexpression of NADH-dependent aspartate-4-semialdehyde dehydrogenase and aspartate dehydrogenase could increase the titer from 11.3 to 13.3 g/L. Next, NADP+-dependent glyceraldehyde-3-phosphate dehydrogenase (NADP-GPD) was coexpressed with that of NAD+-dependent (NAD-GPD) to construct dual-channel glycolysis for balance of intracellular cofactors, which increased the l-homoserine titer by 48.6 % to 16.8 g/L. Finally, engineered strain Cg18-1 accumulated 63.5 g/L l-homoserine after 96 h in a 5 L bioreactor, the highest titer reported to date for C. glutamicum. This dual-channel glycolysis strategy provides a reference for automatic cofactor regulation to promote efficient biosynthesis of other target products.
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Affiliation(s)
- Ning Li
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Lihong Li
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Shiqin Yu
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Jingwen Zhou
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China.
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14
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Hao R, Wang S, Jin X, Yang X, Qi Q, Liang Q. Dynamic and balanced regulation of the thrABC operon gene for efficient synthesis of L-threonine. Front Bioeng Biotechnol 2023; 11:1118948. [PMID: 36937754 PMCID: PMC10018013 DOI: 10.3389/fbioe.2023.1118948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 02/21/2023] [Indexed: 03/06/2023] Open
Abstract
L-threonine is an essential amino acid used widely in food, cosmetics, animal feed and medicine. The thrABC operon plays an important role in regulating the biosynthesis of L-theronine. In this work, we systematically analyzed the effects of separating thrAB and thrC in different proportions on strain growth and L-threonine production in Escherichia coli firstly. The results showed that higher expression of thrC than thrAB enhanced cell growth and L-threonine production; however, L-threonine production decreased when the thrC proportion was too high. The highest L-threonine production was achieved when the expression intensity ratio of thrAB to thrC was 3:5. Secondly, a stationary phase promoter was also used to dynamically regulate the expression of engineered thrABC. This strategy improved cell growth and shortened the fermentation period from 36 h to 24 h. Finally, the acetate metabolic overflow was reduced by deleting the ptsG gene, leading to a further increase in L-threonine production. With these efforts, the final strain P 2.1 -2901ΔptsG reached 40.06 g/L at 60 h fermentation, which was 96.85% higher than the initial control strain TH and the highest reported titer in shake flasks. The maximum L-threonine yield and productivity was obtained in reported fed-batch fermentation, and L-threonine production is close to the highest titer (127.30 g/L). In this work, the expression ratio of genes in the thrABC operon in E. coli was studied systematically, which provided a new approach to improve L-threonine production and its downstream products.
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15
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Pan X, Tang M, You J, Hao Y, Zhang X, Yang T, Rao Z. A Novel Method to Screen Strong Constitutive Promoters in Escherichia coli and Serratia marcescens for Industrial Applications. BIOLOGY 2022; 12:biology12010071. [PMID: 36671763 PMCID: PMC9855843 DOI: 10.3390/biology12010071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/18/2022] [Accepted: 12/28/2022] [Indexed: 01/04/2023]
Abstract
Promoters serve as the switch of gene transcription, playing an important role in regulating gene expression and metabolites production. However, the approach to screening strong constitutive promoters in microorganisms is still limited. In this study, a novel method was designed to identify strong constitutive promoters in E. coli and S. marcescens based on random genomic interruption and fluorescence-activated cell sorting (FACS) technology. First, genomes of E. coli, Bacillus subtilis, and Corynebacterium glutamicum were randomly interrupted and inserted into the upstream of reporter gene gfp to construct three promoter libraries, and a potential strong constitutive promoter (PBS) suitable for E. coli was screened via FACS technology. Second, the core promoter sequence (PBS76) of the screened promoter was identified by sequence truncation. Third, a promoter library of PBS76 was constructed by installing degenerate bases via chemical synthesis for further improving its strength, and the intensity of the produced promoter PBS76-100 was 59.56 times higher than that of the promoter PBBa_J23118. Subsequently, promoters PBBa_J23118, PBS76, PBS76-50, PBS76-75, PBS76-85, and PBS76-100 with different strengths were applied to enhance the metabolic flux of L-valine synthesis, and the L-valine yield was significantly improved. Finally, a strong constitutive promoter suitable for S. marcescens was screened by a similar method and applied to enhance prodigiosin production by 34.81%. Taken together, the construction of a promoter library based on random genomic interruption was effective to screen the strong constitutive promoters for fine-tuning gene expression and reprogramming metabolic flux in various microorganisms.
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Affiliation(s)
- Xuewei Pan
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Mi Tang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Jiajia You
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yanan Hao
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xian Zhang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Taowei Yang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
- Correspondence: ; Tel.: +86-510-85916881
| | - Zhiming Rao
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
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16
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Zhang Z, Yu Z, Wang J, Yu Y, Li L, Sun P, Fan X, Xu Q. Metabolic engineering of Escherichia coli for efficient production of L-5-hydroxytryptophan from glucose. Microb Cell Fact 2022; 21:198. [PMID: 36153615 PMCID: PMC9509612 DOI: 10.1186/s12934-022-01920-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 09/08/2022] [Indexed: 11/10/2022] Open
Abstract
Background 5-hydroxytryptophan (5-HTP), the direct biosynthetic precursor of the neurotransmitter 5-hydroxytryptamine, has been shown to have unique efficacy in the treatment of a variety of disorders, including depression, insomnia, and chronic headaches, and is one of the most commercially valuable amino acid derivatives. However, microbial fermentation for 5-HTP production continues to face many challenges, including low titer/yield and the presence of the intermediate L-tryptophan (L-Trp), owing to the complexity and low activity of heterologous expression in prokaryotes. Therefore, there is a need to construct an efficient microbial cell factory for 5-HTP production. Results We describe the systematic modular engineering of wild-type Escherichia coli for the efficient fermentation of 5-HTP from glucose. First, a xylose-induced T7 RNA polymerase-PT7 promoter system was constructed to ensure the efficient expression of each key heterologous pathway in E. coli. Next, a new tryptophan hydroxylase mutant was used to construct an efficient tryptophan hydroxylation module, and the cofactor tetrahydrobiopterin synthesis and regeneration pathway was expressed in combination. The L-Trp synthesis module was constructed by modifying the key metabolic nodes of tryptophan biosynthesis, and the heterologous synthesis of 5-HTP was achieved. Finally, the NAD(P)H regeneration module was constructed by the moderate expression of the heterologous GDHesi pathway, which successfully reduced the surplus of the intermediate L-Trp. The final engineered strain HTP11 was able to produce 8.58 g/L 5-HTP in a 5-L bioreactor with a yield of 0.095 g/g glucose and a maximum real-time productivity of 0.48 g/L/h, the highest values reported by microbial fermentation. Conclusion In this study, we demonstrate the successful design of a cell factory for high-level 5-HTP production, combined with simple processes that have potential for use in industrial applications in the future. Thus, this study provides a reference for the production of high-value amino acid derivatives using a systematic modular engineering strategy and a basis for an efficient engineered strain development of 5-HTP high-value derivatives. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-022-01920-3.
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17
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Cai M, Zhao Z, Li X, Xu Y, Xu M, Rao Z. Development of a nonauxotrophic L-homoserine hyperproducer in Escherichia coli by systems metabolic engineering. Metab Eng 2022; 73:270-279. [PMID: 35961600 DOI: 10.1016/j.ymben.2022.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 07/14/2022] [Accepted: 08/03/2022] [Indexed: 11/19/2022]
Abstract
L-Homoserine is a valuable amino acid as a platform chemical in the synthesis of various important compounds. Development of microbial strains for high-level L-homoserine production is an attractive research direction in recent years. Herein, we converted a wild-type Escherichia coli to a non-auxotrophic and plasmid-free hyperproducer of L-homoserine using systematically metabolic engineer strategies. First, an initial strain was obtained through regulating L-homoserine degradation pathway and enhancing synthetic flow. To facilitate L-homoserine production, flux-control genes were tuned by optimizing the copy numbers in chromosome, and transport system was modified to promote L-homoserine efflux. Subsequently, a strategy of cofactors synergistic utilization was proposed and successfully applied to achieve L-homoserine hyperproduction. The final engineered strain could efficiently produce 85.29 g/L L-homoserine, which was the highest production level ever reported from a plasmid-free, antibiotic-free, inducer-free and nonauxotrophic strain. These strategies used here can be considered for developing microbial cell factory of other L-aspartate derivatives.
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Affiliation(s)
- Mengmeng Cai
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Zhenqiang Zhao
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Xiangfei Li
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Yuanyi Xu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Meijuan Xu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Zhiming Rao
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, 214122, China.
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18
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Vo TM, Park S. Metabolic engineering of Escherichia coli W3110 for efficient production of homoserine from glucose. Metab Eng 2022; 73:104-113. [PMID: 35803501 DOI: 10.1016/j.ymben.2022.07.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/12/2022] [Accepted: 07/01/2022] [Indexed: 10/17/2022]
Abstract
Efficient microbial cell factory for the production of homoserine from glucose has been developed by iterative and rational engineering of Escherichia coli W3110. The whole pathway from glucose to homoserine was divided into three groups, namely, glucose transport and glycolysis ('up-stream'), TCA and glyoxylate cycles ('mid-stream'), and homoserine module (conversion of aspartate to homoserine and its secretion; 'down-stream'), and the carbon flux in each group as well as between the groups were accelerated and balanced. Altogether, ∼18 genes were modified for active and consistent production of homoserine during both the actively-growing and non-growing stages of cultivation. Finally, fed-batch, two-stage bioreactor experiments, separating the growth from the production stage, were conducted for 61 h, which gave the high titer of 110.8 g/L, yield of 0.64 g/g glucose and volumetric productivity of 1.82 g/L/h, with an insignificant amount of acetate (<0.5 g/L) as the only noticeable byproduct. The metabolic engineering strategy employed in this study should be applicable for the biosynthesis of other amino acids or chemicals derived from aspartic acid.
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Affiliation(s)
- Toan Minh Vo
- School of Energy and Chemical Engineering, UNIST, Ulsan, 44919, South Korea
| | - Sunghoon Park
- School of Energy and Chemical Engineering, UNIST, Ulsan, 44919, South Korea.
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19
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Tian Y, Wang Y, Zhang N, Xiao M, Zhang J, Xing X, Zhang Y, Fan Y, Li X, Nan B, Wang Y, Liu J. Antioxidant Mechanism of Lactiplantibacillus plantarum KM1 Under H2O2 Stress by Proteomics Analysis. Front Microbiol 2022; 13:897387. [PMID: 35832808 PMCID: PMC9271951 DOI: 10.3389/fmicb.2022.897387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 05/26/2022] [Indexed: 11/13/2022] Open
Abstract
Lactiplantibacillus plantarum KM1 was screened from natural fermented products, which had probiotic properties and antioxidant function. The survival rate of L. plantarum KM1 was 78.26% at 5 mM H2O2. In this study, the antioxidant mechanism of L. plantarum KM1 was deeply analyzed by using the proteomics method. The results demonstrated that a total of 112 differentially expressed proteins (DEPs) were screened, of which, 31 DEPs were upregulated and 81 were downregulated. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated that DEPs participated in various metabolic pathways such as pyruvate metabolism, carbon metabolism, trichloroacetic acid cycle, amino acid metabolism, and microbial metabolism in diverse environments. These metabolic pathways were related to oxidative stress caused by H2O2 in L. plantarum KM1. Therefore, the antioxidant mechanism of L. plantarum KM1 under H2O2 stress provided a theoretical basis for its use as a potential natural antioxidant.
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Affiliation(s)
- Yuan Tian
- College of Food Science, Jilin Agricultural University, Changchun, China
- Jilin Province Innovation Center for Food Biological Manufacture, Jilin Agricultural University, Changchun, China
| | - Yu Wang
- College of Food Science, Jilin Agricultural University, Changchun, China
- Jilin Province Innovation Center for Food Biological Manufacture, Jilin Agricultural University, Changchun, China
| | - Nan Zhang
- College of Food Science, Jilin Agricultural University, Changchun, China
- Jilin Province Innovation Center for Food Biological Manufacture, Jilin Agricultural University, Changchun, China
| | - Minmin Xiao
- College of Food Science, Jilin Agricultural University, Changchun, China
- Jilin Province Innovation Center for Food Biological Manufacture, Jilin Agricultural University, Changchun, China
| | - Jing Zhang
- College of Food Science, Jilin Agricultural University, Changchun, China
- Jilin Province Innovation Center for Food Biological Manufacture, Jilin Agricultural University, Changchun, China
| | - Xinyue Xing
- College of Food Science, Jilin Agricultural University, Changchun, China
- Jilin Province Innovation Center for Food Biological Manufacture, Jilin Agricultural University, Changchun, China
| | - Yue Zhang
- College of Food Science, Jilin Agricultural University, Changchun, China
- Jilin Province Innovation Center for Food Biological Manufacture, Jilin Agricultural University, Changchun, China
| | - Yuling Fan
- College of Food Science, Jilin Agricultural University, Changchun, China
- Jilin Province Innovation Center for Food Biological Manufacture, Jilin Agricultural University, Changchun, China
| | - Xia Li
- College of Food Science, Jilin Agricultural University, Changchun, China
- Jilin Province Innovation Center for Food Biological Manufacture, Jilin Agricultural University, Changchun, China
- Xia Li
| | - Bo Nan
- College of Food Science, Jilin Agricultural University, Changchun, China
- Jilin Province Innovation Center for Food Biological Manufacture, Jilin Agricultural University, Changchun, China
| | - Yuhua Wang
- College of Food Science, Jilin Agricultural University, Changchun, China
- Jilin Province Innovation Center for Food Biological Manufacture, Jilin Agricultural University, Changchun, China
- National Processing Laboratory for Soybean Industry and Technology, Changchun, China
- National Engineering Laboratory for Wheat and Corn Deep Processing, Changchun, China
- *Correspondence: Yuhua Wang
| | - Jingsheng Liu
- College of Food Science, Jilin Agricultural University, Changchun, China
- Jilin Province Innovation Center for Food Biological Manufacture, Jilin Agricultural University, Changchun, China
- National Engineering Laboratory for Wheat and Corn Deep Processing, Changchun, China
- Jingsheng Liu
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20
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Wei M, Li G, Xie H, Yang W, Xu H, Han S, Wang J, Meng Y, Xu Q, Li Y, Chen N, Zhang C. Sustainable production of 4-hydroxyisoleucine with minimised carbon loss by simultaneously utilising glucose and xylose in engineered Escherichia coli. BIORESOURCE TECHNOLOGY 2022; 354:127196. [PMID: 35460845 DOI: 10.1016/j.biortech.2022.127196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 04/16/2022] [Accepted: 04/18/2022] [Indexed: 06/14/2023]
Abstract
4-Hydroxyisoleucine is a promising drug for diabetes therapy; however, microbial production of 4-hydroxyisoleucine is not economically efficient because of the carbon loss in the form of CO2. This study aims to achieve de novo synthesis of 4-hydroxyisoleucine with minimised carbon loss in engineered Escherichia coli. Initially, an L-isoleucine-producing strain, ILE-5, was established, and the 4-hydroxyisoleucine synthesis pathway was introduced. The flux toward α-ketoglutarate was enhanced by reinforcing the anaplerotic pathway and disrupting competitive pathways. Subsequently, the metabolic flux for 4-hydroxyisoleucine synthesis was redistributed by dynamically modulating the α-ketoglutarate dehydrogenase complex activity, achieving a 4-hydroxyisoleucine production of 16.53 g/L. Finally, carbon loss was minimised by employing the Weimberg pathway, resulting in a 24.5% decrease in sugar consumption and a 31.6% yield increase. The 4-hydroxyisoleucine production by strain IEOH-11 reached 29.16 g/L in a 5-L fermenter. The 4-hydroxyisoleucine yield (0.29 mol/mol sugar) and productivity (0.91 g/(L⋅h)) were higher than those previously reported.
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Affiliation(s)
- Minhua Wei
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science and Technology, Tianjin 300457, China; College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Guirong Li
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Haixiao Xie
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Wenjun Yang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Haoran Xu
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Shibao Han
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Junzhe Wang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Yan Meng
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Qingyang Xu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science and Technology, Tianjin 300457, China; College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Yanjun Li
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science and Technology, Tianjin 300457, China; College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Ning Chen
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science and Technology, Tianjin 300457, China; College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Chenglin Zhang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science and Technology, Tianjin 300457, China; College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
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21
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Dynamic Regulation of Transporter Expression to Increase L-Threonine Production Using L-Threonine Biosensors. FERMENTATION 2022. [DOI: 10.3390/fermentation8060250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The cytotoxicity of overexpressed transporters limits their application in biochemical production. To overcome this problem, we developed a feedback circuit for L-threonine production that uses a biosensor to regulate transporter expression. First, we used IPTG-induced rhtA regulation, L-threonine exporter, to simulate dynamic regulation for improving L-threonine production, and the results show that it had significant advantages compared with the constitutive overexpression of rhtA. To further construct a feedback circuit for rhtA auto-regulation, three L-threonine sensing promoters, PcysJ, PcysD, and PcysJH, were characterized with gradually decreasing strength. The dynamic expression of rhtA with a threonine-activated promoter considerably increased L-threonine production (21.19 g/L) beyond that attainable by the constitutive expression of rhtA (8.55 g/L). Finally, the autoregulation method was used in regulating rhtB and rhtC to improve L-threonine production and achieve a high titer of 26.78 g/L (a 161.01% increase), a yield of 0.627 g/g glucose, and a productivity of 0.743 g/L/h in shake-flask fermentation. This study analyzed in detail the influence of dynamic regulation and the constitutive expression of transporters on L-threonine production. For the first time, we confirmed that dynamically regulating transporter levels can efficiently promote L-threonine production by using the end-product biosensor.
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22
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Li B, Zhang B, Wang P, Cai X, Chen YY, Yang YF, Liu ZQ, Zheng YG. Rerouting Fluxes of the Central Carbon Metabolism and Relieving Mechanism-Based Inactivation of l-Aspartate-α-decarboxylase for Fermentative Production of β-Alanine in Escherichia coli. ACS Synth Biol 2022; 11:1908-1918. [PMID: 35476404 DOI: 10.1021/acssynbio.2c00055] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
β-Alanine, with the amino group at the β-position, is an important platform chemical that has been widely applied in pharmaceuticals and feed and food additives. However, the current modest titer and productivity, increased fermentation cost, and complicated operation are the challenges for producing β-alanine by microbial fermentation. In this study, a high-yield β-alanine-producing strain was constructed by combining metabolic engineering, protein engineering, and fed-batch bioprocess optimization strategies. First, an aspartate-α-decarboxylase from Bacillus subtilis was introduced in Escherichia coli W3110 to construct an initial β-alanine-producing strain. Production of β-alanine was obviously increased to 4.36 g/L via improving the metabolic flux and reducing carbon loss by rerouting fluxes of the central carbon metabolism. To further increase β-alanine production, mechanism-based inactivation of aspartate-α-decarboxylase was relieved by rational design to maintain the productivity at a high level in β-alanine fed-batch fermentation. Finally, fed-batch bioprocess optimization strategies were used to improve β-alanine production to 85.18 g/L with 0.24 g/g glucose yield and 1.05 g/L/h productivity in fed-batch fermentation. These strategies can be effectively used in the construction of engineered strains for β-alanine and production of its derivatives, and the final engineered strain was a valuable microbial cell factory that can be used for the industrial production of β-alanine.
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Affiliation(s)
- Bo Li
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, P. R. China
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, P. R. China
| | - Bo Zhang
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, P. R. China
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, P. R. China
| | - Pei Wang
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, P. R. China
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, P. R. China
| | - Xue Cai
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, P. R. China
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, P. R. China
| | - Yuan-Yuan Chen
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, P. R. China
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, P. R. China
| | - Yu-Feng Yang
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, P. R. China
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, P. R. China
| | - Zhi-Qiang Liu
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, P. R. China
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, P. R. China
| | - Yu-Guo Zheng
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, P. R. China
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, P. R. China
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23
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Li N, Zeng W, Zhou J, Xu S. O-Acetyl-L-homoserine production enhanced by pathway strengthening and acetate supplementation in Corynebacterium glutamicum. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:27. [PMID: 35287716 PMCID: PMC8922893 DOI: 10.1186/s13068-022-02114-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 01/29/2022] [Indexed: 11/10/2022]
Abstract
BACKGROUND O-Acetyl-L-homoserine (OAH) is an important potential platform chemical. However, low levels of production of OAH are greatly limiting its industrial application. Furthermore, as a common and safe amino acid-producing strain, Corynebacterium glutamicum has not yet achieved efficient production of OAH. RESULTS First, exogenous L-homoserine acetyltransferase was introduced into an L-homoserine-producing strain, resulting in the accumulation of 0.98 g/L of OAH. Second, by comparing different acetyl-CoA biosynthesis pathways and adding several feedstocks (acetate, citrate, and pantothenate), the OAH titer increased 2.3-fold to 3.2 g/L. Then, the OAH titer further increased by 62.5% when the expression of L-homoserine dehydrogenase and L-homoserine acetyltransferase was strengthened via strong promoters. Finally, the engineered strain produced 17.4 g/L of OAH in 96 h with acetate as the supplementary feedstock in a 5-L bioreactor. CONCLUSIONS This is the first report on the efficient production of OAH with C. glutamicum as the chassis, which would provide a good foundation for industrial production of OAH.
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Affiliation(s)
- Ning Li
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Weizhu Zeng
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Jingwen Zhou
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Sha Xu
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China. .,Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.
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24
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Chong JWR, Khoo KS, Yew GY, Leong WH, Lim JW, Lam MK, Ho YC, Ng HS, Munawaroh HSH, Show PL. Advances in production of bioplastics by microalgae using food waste hydrolysate and wastewater: A review. BIORESOURCE TECHNOLOGY 2021; 342:125947. [PMID: 34563823 DOI: 10.1016/j.biortech.2021.125947] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/09/2021] [Accepted: 09/12/2021] [Indexed: 06/13/2023]
Abstract
Microalgae have emerged as an effective dual strategy for bio-valorisation of food processing wastewater and food waste hydrolysate which favours microalgae cultivation into producing value-added by products mainly lipids, carbohydrates, and proteins to the advantages of bioplastic production. Moreover, various microalgae have successfully removed high amount of organic pollutants from food processing wastewater prior discharging into the environment. Innovation of microalgae cultivating in food processing wastewater greatly reduced the cost of wastewater treatment compared to conventional approach in terms of lower carbon emissions, energy consumption, and chemical usage while producing microalgae biomass which can benefit low-cost fertilizer and bioplastic applications. The study on several microalgae species has all successfully grown on food waste hydrolysates showing high exponential growth rate and biomass production rich in proteins, lipids, carbohydrates, and fatty acids. Multiple techniques have been implemented for the extraction of food wastes to be incorporate into the bioplastic production.
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Affiliation(s)
- Jun Wei Roy Chong
- Department of Chemical and Environmental Engineering, Faculty of Science and Engineering, University of Nottingham Malaysia, Jalan Broga, 43500 Semenyih, Selangor Darul Ehsan, Malaysia
| | - Kuan Shiong Khoo
- Department of Chemical and Environmental Engineering, Faculty of Science and Engineering, University of Nottingham Malaysia, Jalan Broga, 43500 Semenyih, Selangor Darul Ehsan, Malaysia; Faculty of Applied Sciences, UCSI University, No. 1, Jalan Menara Gading, UCSI Heights, Cheras, 56000 Kuala Lumpur, Malaysia
| | - Guo Yong Yew
- Department of Chemical and Environmental Engineering, Faculty of Science and Engineering, University of Nottingham Malaysia, Jalan Broga, 43500 Semenyih, Selangor Darul Ehsan, Malaysia
| | - Wai Hong Leong
- HICoE-Centre for Biofuel and Biochemical Research, Institute of Self-Sustainable Building, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia; Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia
| | - Jun Wei Lim
- HICoE-Centre for Biofuel and Biochemical Research, Institute of Self-Sustainable Building, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia; Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia
| | - Man Kee Lam
- HICoE-Centre for Biofuel and Biochemical Research, Institute of Self-Sustainable Building, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia; Chemical Engineering Department, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia
| | - Yeek-Chia Ho
- Civil and Environmental Engineering Department, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia; Centre for Urban Resource Sustainability, Institute of Self-Sustainable Building, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia
| | - Hui Suan Ng
- Faculty of Applied Sciences, UCSI University, No. 1, Jalan Menara Gading, UCSI Heights, Cheras, 56000 Kuala Lumpur, Malaysia
| | - Heli Siti Halimatul Munawaroh
- Study Program of Chemistry, Department of Chemistry Education, Universitas Pendidikan Indonesia, Jalan Dr. Setiabudi 229, Bandung 40154, West Java, Indonesia
| | - Pau Loke Show
- Department of Chemical and Environmental Engineering, Faculty of Science and Engineering, University of Nottingham Malaysia, Jalan Broga, 43500 Semenyih, Selangor Darul Ehsan, Malaysia.
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25
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Li B, Zhang B, Wang P, Cai X, Tang YQ, Jin JY, Liang JX, Liu ZQ, Zheng YG. Targeting metabolic driving and minimization of by-products synthesis for high-yield production of D-pantothenate in Escherichia coli. Biotechnol J 2021; 17:e2100431. [PMID: 34705325 DOI: 10.1002/biot.202100431] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/25/2021] [Accepted: 10/25/2021] [Indexed: 01/02/2023]
Abstract
BACKGROUND d-Pantothenate (DPA) is an important functional chemical that has been widely applied in healthcare, cosmetics, animal food, and feed industries. METHODS AND RESULTS In this study, a high-yield DPA-producing strain was constructed by metabolic engineering strategies with targeting metabolic driving and by-products minimization. The metabolic driving force of push and pull was firstly obtained to improve the production of DPA via enrichment of precursor pool and synthetic pathway, accumulating 4.29 g L-1 DPA in shake flask fermentation. To eliminate the metabolic pressure on DPA production, an amino throttling system was proposed and successfully attenuated the synthesis of four competitive amino acids by a single-step regulation of gdhA. Further minimization of acetate was carried out by pta deletion, and utilization of β-alanine was improved via enhancing its uptake system with producing 5.78 g L-1 DPA. Finally, the engineered strain produced 66.39 g L-1 DPA with β-alanine addition in fermentor under fed-batch fermentation. CONCLUSION This study paved a foundation for the industrial production of DPA.
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Affiliation(s)
- Bo Li
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, P. R. China.,The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, P. R. China
| | - Bo Zhang
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, P. R. China.,The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, P. R. China
| | - Pei Wang
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, P. R. China.,The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, P. R. China
| | - Xue Cai
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, P. R. China.,The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, P. R. China
| | - Ya-Qun Tang
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, P. R. China.,The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, P. R. China
| | - Jie-Yi Jin
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, P. R. China.,The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, P. R. China
| | - Jin-Xi Liang
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, P. R. China.,The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, P. R. China
| | - Zhi-Qiang Liu
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, P. R. China.,The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, P. R. China
| | - Yu-Guo Zheng
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, P. R. China.,The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, P. R. China
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26
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Jiang S, Wang D, Wang R, Zhao C, Ma Q, Wu H, Xie X. Reconstructing a recycling and nonauxotroph biosynthetic pathway in Escherichia coli toward highly efficient production of L-citrulline. Metab Eng 2021; 68:220-231. [PMID: 34688880 DOI: 10.1016/j.ymben.2021.10.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 09/28/2021] [Accepted: 10/19/2021] [Indexed: 10/20/2022]
Abstract
L-citrulline is a high-value amino acid with promising application in medicinal and food industries. Construction of highly efficient microbial cell factories for L-citrulline production is still an open issue due to complex metabolic flux distribution and L-arginine auxotrophy. In this study, we constructed a nonauxotrophic cell factory in Escherichia coli for high-titer L-citrulline production by coupling modular engineering strategies with dynamic pathway regulation. First, the biosynthetic pathway of L-citrulline was enhanced after blockage of the degradation pathway and introduction of heterologous biosynthetic genes from Corynebacterium glutamicum. Specifically, a superior recycling biosynthetic pathway was designed to replace the native linear pathway by deleting native acetylornithine deacetylase. Next, the carbamoyl phosphate and L-glutamate biosynthetic modules, the NADPH generation module, and the efflux module were modified to increase L-citrulline titer further. Finally, a toggle switch that responded to cell density was designed to dynamically control the expression of the argG gene and reconstruct a nonauxotrophic pathway. Without extra supplement of L-arginine during fermentation, the final CIT24 strain produced 82.1 g/L L-citrulline in a 5-L bioreactor with a yield of 0.34 g/g glucose and a productivity of 1.71 g/(L ⋅ h), which were the highest values reported by microbial fermentation. Our study not only demonstrated the successful design of cell factory for high-level L-citrulline production but also provided references of coupling the rational module engineering strategies and dynamic regulation strategies to produce high-value intermediate metabolites.
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Affiliation(s)
- Shuai Jiang
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, Tianjin University of Science & Technology, Tianjin, 300457, PR China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, PR China
| | - Dehu Wang
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, Tianjin University of Science & Technology, Tianjin, 300457, PR China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, PR China
| | - Ruirui Wang
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, Tianjin University of Science & Technology, Tianjin, 300457, PR China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, PR China
| | - Chunguang Zhao
- Ningxia Eppen Biotech Co, Ltd, Ningxia, 750000, PR China
| | - Qian Ma
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, Tianjin University of Science & Technology, Tianjin, 300457, PR China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, PR China
| | - Heyun Wu
- College of Food Science and Engineering, Tianjin University of Science & Technology, Tianjin, 300457, PR China.
| | - Xixian Xie
- Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education, Tianjin University of Science & Technology, Tianjin, 300457, PR China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin, 300457, PR China.
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27
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Ma Q, Xia L, Wu H, Zhuo M, Yang M, Zhang Y, Tan M, Zhao K, Sun Q, Xu Q, Chen N, Xie X. Metabolic engineering of Escherichia coli for efficient osmotic stress-free production of compatible solute hydroxyectoine. Biotechnol Bioeng 2021; 119:89-101. [PMID: 34612520 DOI: 10.1002/bit.27952] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/22/2021] [Accepted: 09/28/2021] [Indexed: 11/08/2022]
Abstract
Compatible solutes are key for the ability of halophilic bacteria to resist high osmotic stress. They have received wide attention from researchers for their excellent osmotic protection properties. Hydroxyectoine is a particularly important compatible solute, but its production by microbes faces several challenges, including low titer/yield, the presence of the byproduct ectoine, and the requirement of high salinity. Here, we aimed to metabolically engineer Escherichia coli to efficiently produce hydroxyectoine in the absence of osmotic stress without accumulating the byproduct ectoine. First, combinatorial optimization of the expression strength of key genes in the ectoine synthesis module and hydroxyectoine synthesis module was conducted. After optimization of the expression of these genes, 12.12 g/L hydroxyectoine and 0.24 g/L ectoine were obtained at 36 h in shake-flask fermentation with the addition of the co-substrate α-ketoglutarate. Further optimization of the addition of α-ketoglutarate achieved the sole production of hydroxyectoine (i.e., no ectoine accumulation), indicating that the supply of α-ketoglutarate is critically important for sole hydroxyectoine production. Finally, quorum sensing-based auto-regulation of intracellular α-ketoglutarate pool was implemented as an alternative to α-ketoglutarate addition by coupling the expression of sucA with the esaI/esaR circuit, which led to 14.93 g/L hydroxyectoine with a unit cell yield of 1.678 g/g and no ectoine accumulation in the absence of osmotic stress. This is the highest reported titer of sole hydroxyectoine production under salinity-free fermentation to date.
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Affiliation(s)
- Qian Ma
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China.,National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology, Tianjin, China
| | - Li Xia
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Heyun Wu
- College of Food Science and Engineering, Tianjin University of Science and Technology, Tianjin, China
| | - Mingyang Zhuo
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Mengya Yang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Ying Zhang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Miao Tan
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Kexin Zhao
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Quanwei Sun
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Qingyang Xu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China.,National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology, Tianjin, China
| | - Ning Chen
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China.,National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology, Tianjin, China
| | - Xixian Xie
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China.,National and Local United Engineering Lab of Metabolic Control Fermentation Technology, Tianjin University of Science and Technology, Tianjin, China
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Mu Q, Zhang S, Mao X, Tao Y, Yu B. Highly efficient production of L-homoserine in Escherichia coli by engineering a redox balance route. Metab Eng 2021; 67:321-329. [PMID: 34329706 DOI: 10.1016/j.ymben.2021.07.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 06/30/2021] [Accepted: 07/26/2021] [Indexed: 12/29/2022]
Abstract
L-Homoserine is a nonessential chiral amino acid and the precursor of L-threonine and L-methionine. It has great potential to be used in the pharmaceutical, agricultural, cosmetic, and fragrance industries. However, the current low efficiency in the fermentation process of L-homoserine drives up the cost and therefore limits applications. Here, we systematically analyzed the L-homoserine production network in Escherichia coli to design a redox balance route for L-homoserine fermentation from glucose. Production of L-homoserine from L-aspartate via reduction of the tricarboxylic acid cycle intermediate oxaloacetate lacks reducing power. This deficiency could be corrected by activating the glyoxylate shunt and driving the flux from fumarate to L-aspartate with excess reducing power. This redox balance route decreases cell growth pressure and the theoretical yield of L-homoserine is 1.5 mol/mol of glucose without carbon loss. We fine-tuned the flux from fumarate to L-aspartate, deleted competitive and degradative pathways, enhanced L-homoserine efflux, and generated 84.1 g/L L-homoserine with 1.96 g/L/h productivity and 0.50 g/g glucose yield in a fed-batch fermentation. This study proposes a novel balanced redox metabolic network strategy for highly efficient production of L-homoserine and its derivative amino acids.
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Affiliation(s)
- Qingxuan Mu
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shasha Zhang
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xianjun Mao
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
| | - Yong Tao
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bo Yu
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
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