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Fatema N, Li X, Gan Q, Fan C. Characterizing lysine acetylation of glucokinase. Protein Sci 2024; 33:e4845. [PMID: 37996965 PMCID: PMC10731539 DOI: 10.1002/pro.4845] [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: 09/25/2023] [Revised: 11/16/2023] [Accepted: 11/18/2023] [Indexed: 11/25/2023]
Abstract
Glucokinase (GK) catalyzes the phosphorylation of glucose to form glucose-6-phosphate as the substrate of glycolysis for energy production. Acetylation of lysine residues in Escherichia coli GK has been identified at multiple sites by a series of proteomic studies, but the impact of acetylation on GK functions remains largely unknown. In this study, we applied the genetic code expansion strategy to produce site-specifically acetylated GK variants which naturally exist in cells. Enzyme assays and kinetic analyses showed that lysine acetylation decreases the GK activity, mostly resulting from acetylation of K214 and K216 at the entrance of the active site, which impairs the binding of substrates. We also compared results obtained from the glutamine substitution method and the genetic acetyllysine incorporation approach, showing that glutamine substitution is not always effective for mimicking acetylated lysine. Further genetic studies as well as in vitro acetylation and deacetylation assays were performed to determine acetylation and deacetylation mechanisms, which showed that E. coli GK could be acetylated by acetyl-phosphate without enzymes and deacetylated by CobB deacetylase.
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Affiliation(s)
- Nour Fatema
- Cell and Molecular Biology ProgramUniversity of ArkansasFayettevilleArkansasUSA
| | - Xinyu Li
- Cell and Molecular Biology ProgramUniversity of ArkansasFayettevilleArkansasUSA
| | - Qinglei Gan
- Department of Chemistry and BiochemistryUniversity of ArkansasFayettevilleArkansasUSA
| | - Chenguang Fan
- Cell and Molecular Biology ProgramUniversity of ArkansasFayettevilleArkansasUSA
- Department of Chemistry and BiochemistryUniversity of ArkansasFayettevilleArkansasUSA
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2
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Wang Y, Bai Y, Zeng Q, Jiang Z, Liu Y, Wang X, Liu X, Liu C, Min W. Recent advances in the metabolic engineering and physiological opportunities for microbial synthesis of L-aspartic acid family amino acids: A review. Int J Biol Macromol 2023; 253:126916. [PMID: 37716660 DOI: 10.1016/j.ijbiomac.2023.126916] [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: 07/24/2023] [Revised: 09/10/2023] [Accepted: 09/13/2023] [Indexed: 09/18/2023]
Abstract
L-aspartic acid, L-threonine, L-isoleucine, l-lysine, and L-methionine constitute the l-aspartate amino acids (AFAAs). Except for L-aspartic acid, these are essential amino acids that cannot be synthesized by humans or animals themselves. E. coli and C. glutamicum are the main model organisms for AFAA production. It is necessary to reconstitute microbial cell factories and the physiological state of industrial fermentation cells for in-depth research into strains with higher AFAA production levels and optimal growth states. Considering that the anabolic pathways of the AFAAs and engineering modifications have rarely been reviewed in the latest progress, this work reviews the central metabolic pathways of two strains and strategies for the metabolic engineering of AFAA synthetic pathways. The challenges posed by microbial physiology in AFAA production and possible strategies to address them, as well as future research directions for constructing strains with high AFAA production levels, are discussed in this review article.
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Affiliation(s)
- Yusheng Wang
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, PR China
| | - Yunlong Bai
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, PR China
| | - Qi Zeng
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, PR China
| | - Zeyuan Jiang
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, PR China
| | - Yuzhe Liu
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, PR China
| | - Xiyan Wang
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, PR China
| | - Xiaoting Liu
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, PR China
| | - Chunlei Liu
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, PR China.
| | - Weihong Min
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, PR China.
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Campbell RP, Whittington AC, Zorio DAR, Miller BG. Recruitment of a Middling Promiscuous Enzyme Drives Adaptive Metabolic Evolution in Escherichia coli. Mol Biol Evol 2023; 40:msad202. [PMID: 37708398 PMCID: PMC10519446 DOI: 10.1093/molbev/msad202] [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: 04/18/2023] [Revised: 08/29/2023] [Accepted: 09/05/2023] [Indexed: 09/16/2023] Open
Abstract
A key step in metabolic pathway evolution is the recruitment of promiscuous enzymes to perform new functions. Despite the recognition that promiscuity is widespread in biology, factors dictating the preferential recruitment of one promiscuous enzyme over other candidates are unknown. Escherichia coli contains four sugar kinases that are candidates for recruitment when the native glucokinase machinery is deleted-allokinase (AlsK), manno(fructo)kinase (Mak), N-acetylmannosamine kinase (NanK), and N-acetylglucosamine kinase (NagK). The catalytic efficiencies of these enzymes are 103- to 105-fold lower than native glucokinases, ranging from 2,400 M-1 s-1 for the most active candidate, NagK, to 15 M-1 s-1 for the least active candidate, AlsK. To investigate the relationship between catalytic activities of promiscuous enzymes and their recruitment, we performed adaptive evolution of a glucokinase-deficient E. coli strain to restore glycolytic metabolism. We observed preferential recruitment of NanK via a trajectory involving early mutations that facilitate glucose uptake and amplify nanK transcription, followed by nonsynonymous substitutions in NanK that enhance the enzyme's promiscuous glucokinase activity. These substitutions reduced the native activity of NanK and reduced organismal fitness during growth on an N-acetylated carbon source, indicating that enzyme recruitment comes at a cost for growth on other substrates. Notably, the two most active candidates, NagK and Mak, were not recruited, suggesting that catalytic activity alone does not dictate evolutionary outcomes. The results highlight our lack of knowledge regarding biological drivers of enzyme recruitment and emphasize the need for a systems-wide approach to identify factors facilitating or constraining this important adaptive process.
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Affiliation(s)
- Ryan P Campbell
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, USA
| | - A Carl Whittington
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, USA
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Diego A R Zorio
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Brian G Miller
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, USA
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4
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Liu S, Wang BB, Xu JZ, Zhang WG. Engineering of Shikimate Pathway and Terminal Branch for Efficient Production of L-Tryptophan in Escherichia coli. Int J Mol Sci 2023; 24:11866. [PMID: 37511626 PMCID: PMC10380740 DOI: 10.3390/ijms241411866] [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: 06/14/2023] [Revised: 07/19/2023] [Accepted: 07/20/2023] [Indexed: 07/30/2023] Open
Abstract
L-tryptophan (L-trp), produced through bio-manufacturing, is widely used in the pharmaceutical and food industries. Based on the previously developed L-trp-producing strain, this study significantly improved the titer and yield of L-trp, through metabolic engineering of the shikimate pathway and the L-tryptophan branch. First, the rate-limiting steps in the shikimate pathway were investigated and deciphered, revealing that the combined overexpression of the genes aroE and aroD increased L-trp production. Then, L-trp synthesis was further enhanced at the shaking flask level by improving the intracellular availability of L-glutamine (L-gln) and L-serine (L-ser). In addition, the transport system and the competing pathway of L-trp were also modified, indicating that elimination of the gene TnaB contributed to the extracellular accumulation of L-trp. Through optimizing formulas, the robustness and production efficiency of engineered strains were enhanced at the level of the 30 L fermenter. After 42 h of fed-batch fermentation, the resultant strain produced 53.65 g/L of L-trp, with a yield of 0.238 g/g glucose. In this study, the high-efficiency L-trp-producing strains were created in order to establish a basis for further development of more strains for the production of other highly valuable aromatic compounds or their derivatives.
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Affiliation(s)
- Shuai Liu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800# Lihu Road, Wuxi 214122, China
| | - Bing-Bing Wang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800# Lihu Road, Wuxi 214122, China
| | - Jian-Zhong Xu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800# Lihu Road, Wuxi 214122, China
| | - Wei-Guo Zhang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800# Lihu Road, Wuxi 214122, China
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Kolasinliler G, Aagre MM, Akkale C, Kaya HB. The use of CRISPR-Cas-based systems in bacterial cell factories. Biochem Eng J 2023. [DOI: 10.1016/j.bej.2023.108880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
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6
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Fu B, Ying J, Chen Q, Zhang Q, Lu J, Zhu Z, Yu P. Enhancing the biosynthesis of riboflavin in the recombinant Escherichia coli BL21 strain by metabolic engineering. Front Microbiol 2023; 13:1111790. [PMID: 36726568 PMCID: PMC9885008 DOI: 10.3389/fmicb.2022.1111790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 12/29/2022] [Indexed: 01/18/2023] Open
Abstract
In this study, to construct the riboflavin-producing strain R1, five key genes, ribA, ribB, ribC, ribD, and ribE, were cloned and ligated to generate the plasmid pET-AE, which was overexpressed in Escherichia coli BL21. The R1 strain accumulated 182.65 ± 9.04 mg/l riboflavin. Subsequently, the R2 strain was constructed by the overexpression of zwf harboring the constructed plasmid pAC-Z in the R1 strain. Thus, the level of riboflavin in the R2 strain increased to 319.01 ± 20.65 mg/l (74.66% increase). To further enhance ribB transcript levels and riboflavin production, the FMN riboswitch was deleted from E. coli BL21 with CRISPR/Cas9 to generate the R3 strain. The R4 strain was constructed by cotransforming pET-AE and pAC-Z into the R3 strain. Compared to those of E. coli BL21, the ribB transcript levels of R2 and R4 improved 2.78 and 3.05-fold, respectively. The R4 strain accumulated 437.58 ± 14.36 mg/l riboflavin, increasing by 37.17% compared to the R2 strain. These results suggest that the deletion of the FMN riboswitch can improve the transcript level of ribB and facilitate riboflavin production. A riboflavin titer of 611.22 ± 11.25 mg/l was achieved under the optimal fermentation conditions. Ultimately, 1574.60 ± 109.32 mg/l riboflavin was produced through fed-batch fermentation with 40 g/l glucose. This study contributes to the industrial production of riboflavin by the recombinant E. coli BL21.
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Affiliation(s)
- Bing Fu
- College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang, China,College of Forestry Science and Technology, Lishui Vocational and Technical College, Lishui, Zhejiang, China
| | - Junhui Ying
- College of Forestry Science and Technology, Lishui Vocational and Technical College, Lishui, Zhejiang, China
| | - Qingwei Chen
- College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang, China
| | - Qili Zhang
- College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang, China
| | - Jiajie Lu
- College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang, China
| | - Zhiwen Zhu
- College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang, China
| | - Ping Yu
- College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang, China,*Correspondence: Ping Yu,
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Wang G, Li Q, Zhang Z, Yin X, Wang B, Yang X. Recent progress in adaptive laboratory evolution of industrial microorganisms. J Ind Microbiol Biotechnol 2022; 50:6794275. [PMID: 36323428 PMCID: PMC9936214 DOI: 10.1093/jimb/kuac023] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Accepted: 10/24/2022] [Indexed: 01/12/2023]
Abstract
Adaptive laboratory evolution (ALE) is a technique for the selection of strains with better phenotypes by long-term culture under a specific selection pressure or growth environment. Because ALE does not require detailed knowledge of a variety of complex and interactive metabolic networks, and only needs to simulate natural environmental conditions in the laboratory to design a selection pressure, it has the advantages of broad adaptability, strong practicability, and more convenient transformation of strains. In addition, ALE provides a powerful method for studying the evolutionary forces that change the phenotype, performance, and stability of strains, resulting in more productive industrial strains with beneficial mutations. In recent years, ALE has been widely used in the activation of specific microbial metabolic pathways and phenotypic optimization, the efficient utilization of specific substrates, the optimization of tolerance to toxic substance, and the biosynthesis of target products, which is more conducive to the production of industrial strains with excellent phenotypic characteristics. In this paper, typical examples of ALE applications in the development of industrial strains and the research progress of this technology are reviewed, followed by a discussion of its development prospects.
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Affiliation(s)
| | | | - Zhan Zhang
- Technology Center, China Tobacco Henan Industrial Co., Ltd. Zhengzhou, Henan 450000, People's Republic of China
| | - Xianzhong Yin
- Technology Center, China Tobacco Henan Industrial Co., Ltd. Zhengzhou, Henan 450000, People's Republic of China
| | - Bingyang Wang
- Laboratory of Biotransformation and Biocatalysis, School of Tobacco Science and Engineering, Zhengzhou University of Light Industry, Zhengzhou, Henan 450000, People's Republic of China
| | - Xuepeng Yang
- Correspondence should be addressed to: Xuepeng Yang, Zhengzhou University of Light Industry, Dongfeng Road 5, Zhengzhou, Henan 450002, People's Republic of China. Tel.: +86-152-3712-7687. Fax: +86-0371-8660-8262. E-mail:
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8
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Chen M, Liang H, Han C, Zhou P, Xing Z, Chen Q, Liu Y, Xie GA, Xie R. Engineering of global transcription factor FruR to redirect the carbon flow in Escherichia coli for enhancing L-phenylalanine biosynthesis. Microb Cell Fact 2022; 21:222. [PMID: 36289548 PMCID: PMC9609185 DOI: 10.1186/s12934-022-01954-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 10/13/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The catabolite repressor/activator protein (FruR) is a global regulatory protein known to control the expression of several genes concerned with carbon utilization and energy metabolism. This study aimed to illustrate effects of the FruR mutant on the L-phenylalanine (L-PHE) producing strain PHE01. RESULTS Random mutagenesis libraries of fruR generated in vitro were first integrated into the chromosome of PHE01 by CRISPR/Cas9 technique, and then the best mutant PHE07 (FruRE173K) was obtained. With this mutant, a final L-PHE concentration of 70.50 ± 1.02 g/L was achieved, which was 23.34% higher than that of PHE01. To better understand the mechanism, both transcriptomes and metabolomes of PHE07 were carried out and compared to that of PHE01. Specifically, the transcript levels of genes involved in gluconeogenesis pathway, pentose phosphate pathway, Krebs cycle, and glyoxylate shunt were up-regulated in the FruRE173K mutant, whereas genes aceEF, acnB, and icd were down-regulated. From the metabolite level, the FruRE173K mutation led to an accumulation of pentose phosphate pathway and Krebs cycle products, whereas the products of pyruvate metabolism pathway: acetyl-CoA and cis-aconic acid, were down-regulated. As a result of the altered metabolic flows, the utilization of carbon sources was improved and the supply of precursors (phosphoenolpyruvate and erythrose 4-phosphate) for L-PHE biosynthesis was increased, which together led to the enhanced production of L-PHE. CONCLUSION A novel strategy for L-PHE overproduction by modification of the global transcription factor FruR in E. coli was reported. Especially, these findings expand the scope of pathways affected by the fruR regulon and illustrate its importance as a global regulator in L-PHE production.
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Affiliation(s)
- Minliang Chen
- Henan Joincare Biopharma Research Institute Co. Ltd, Jinyuan Street 8, Jiaozuo, 454000 People’s Republic of China ,Guangdong Provincial Key Laboratory of Research and Development and Application of Fermentation and Semi-Synthetic Drugs, Livzon New North River Pharmaceutical Co. Ltd, 1st Renmin Road, Qingyuan, 511500 People’s Republic of China
| | - Hengyu Liang
- Henan Joincare Biopharma Research Institute Co. Ltd, Jinyuan Street 8, Jiaozuo, 454000 People’s Republic of China ,Jiaozuo Joincare Biotechnology Co. Ltd, Jinyuan Street 8, Jiaozuo, 454000 People’s Republic of China ,Guangdong Provincial Key Laboratory of Research and Development and Application of Fermentation and Semi-Synthetic Drugs, Livzon New North River Pharmaceutical Co. Ltd, 1st Renmin Road, Qingyuan, 511500 People’s Republic of China
| | - Chao Han
- Henan Joincare Biopharma Research Institute Co. Ltd, Jinyuan Street 8, Jiaozuo, 454000 People’s Republic of China ,Guangdong Provincial Key Laboratory of Research and Development and Application of Fermentation and Semi-Synthetic Drugs, Livzon New North River Pharmaceutical Co. Ltd, 1st Renmin Road, Qingyuan, 511500 People’s Republic of China
| | - Peng Zhou
- Henan Joincare Biopharma Research Institute Co. Ltd, Jinyuan Street 8, Jiaozuo, 454000 People’s Republic of China ,Guangdong Provincial Key Laboratory of Research and Development and Application of Fermentation and Semi-Synthetic Drugs, Livzon New North River Pharmaceutical Co. Ltd, 1st Renmin Road, Qingyuan, 511500 People’s Republic of China
| | - Zhiwei Xing
- Henan Joincare Biopharma Research Institute Co. Ltd, Jinyuan Street 8, Jiaozuo, 454000 People’s Republic of China ,Jiaozuo Joincare Biotechnology Co. Ltd, Jinyuan Street 8, Jiaozuo, 454000 People’s Republic of China
| | - Qianqian Chen
- Guangdong Provincial Key Laboratory of Research and Development and Application of Fermentation and Semi-Synthetic Drugs, Livzon New North River Pharmaceutical Co. Ltd, 1st Renmin Road, Qingyuan, 511500 People’s Republic of China
| | - Yongyu Liu
- Henan Joincare Biopharma Research Institute Co. Ltd, Jinyuan Street 8, Jiaozuo, 454000 People’s Republic of China
| | - Gou-an Xie
- Henan Joincare Biopharma Research Institute Co. Ltd, Jinyuan Street 8, Jiaozuo, 454000 People’s Republic of China
| | - Rufei Xie
- Henan Joincare Biopharma Research Institute Co. Ltd, Jinyuan Street 8, Jiaozuo, 454000 People’s Republic of China
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Wang X, Xiong K, Huang F, Huang J, Liu Q, Duan N, Ruan H, Jiang H, Zhu Y, Lin L, Song Y, Zhao M, Zheng L, Ye P, Qian Y, Hu Q, Yan F, Wang W. A metagenome-wide association study of the gut microbiota in recurrent aphthous ulcer and regulation by thalidomide. Front Immunol 2022; 13:1018567. [PMID: 36341405 PMCID: PMC9626999 DOI: 10.3389/fimmu.2022.1018567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Accepted: 09/30/2022] [Indexed: 12/04/2022] Open
Abstract
Recurrent aphthous ulcer (RAU), one of the most common diseases in humans, has an unknown etiology and is difficult to treat. Thalidomide is an important immunomodulatory and antitumor drug and its effects on the gut microbiota still remain unclear. We conducted a metagenomic sequencing study of fecal samples from a cohort of individuals with RAU, performed biochemical assays of cytokines, immunoglobulins and antimicrobial peptides in serum and saliva, and investigated the regulation effects of thalidomide administration and withdrawal. Meanwhile we constructed the corresponding prediction models. Our metagenome-wide association results indicated that gut dysbacteriosis, microbial dysfunction and immune imbalance occurred in RAU patients. Thalidomide regulated gut dysbacteriosis in a species-specific manner and had different sustainable effects on various probiotics and pathogens. A previously unknown association between gut microbiota alterations and RAU was found, and the specific roles of thalidomide in modulating the gut microbiota and immunity were determined, suggesting that RAU may be affected by targeting gut dysbacteriosis and modifying immune imbalance. In-depth insights into sophisticated networks consisting of the gut microbiota and host cells may lead to the development of emerging treatments, including prebiotics, probiotics, synbiotics, and postbiotics.
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Affiliation(s)
- Xiang Wang
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China
| | - Kexu Xiong
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Fan Huang
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China
| | - Jinqun Huang
- Beijing Genomics Institute (BGI)-genomics, BGI-Shenzhen, Shenzhen, China
| | - Qin Liu
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China
| | - Ning Duan
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China
| | - Huanhuan Ruan
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China
| | - Hongliu Jiang
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China
| | - Yanan Zhu
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China
| | - Lin Lin
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China
| | - Yuefeng Song
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China
| | - Maomao Zhao
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China
| | - Lichun Zheng
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China
| | - Pei Ye
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China
| | - Yajie Qian
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China
| | - Qingang Hu
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China
- *Correspondence: Wenmei Wang, ; Fuhua Yan, ; Qingang Hu,
| | - Fuhua Yan
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China
- *Correspondence: Wenmei Wang, ; Fuhua Yan, ; Qingang Hu,
| | - Wenmei Wang
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China
- *Correspondence: Wenmei Wang, ; Fuhua Yan, ; Qingang Hu,
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10
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Jiao P, Zhang X, Wei Y, Wang P. Simulation of Adsorption Process of l-Tryptophan on Mixed-Mode Resin HD-1 with Combined Physical Adsorption and Ion Exchange. ACS OMEGA 2022; 7:35331-35338. [PMID: 36211030 PMCID: PMC9535704 DOI: 10.1021/acsomega.2c05194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023]
Abstract
The mass-transfer process of l-tryptophan (l-Trp) in the hydrophobic interaction/ion-exchange mixed-mode resin HD-1 particles and fixed bed was studied experimentally and theoretically. The adsorption kinetics of l-Trp in single-component and multicomponent adsorption systems was investigated under different pH conditions. The co-adsorption of sodium ions (Na+) and l-Trp anions was found to be negligible. A modified liquid-film linear driving force model considering the physical adsorption of l-Trp zwitterions and anions as well as ion exchange of l-Trp cations was proposed. The dissociation equilibria of l-Trp molecules and functional groups on the resin were introduced in the model. The model could well fit the kinetic adsorption curves of l-Trp at different pH values. The presence of Na+ and the impurity amino acid l-glutamic acid (l-Glu) did not significantly affect the mass-transfer rate of l-Trp. The dynamic adsorption processes of l-Trp under different pH and concentration conditions were studied. A modified transport-dispersive model considering axial diffusion, liquid-film mass transfer, and a combined physical adsorption and ion-exchange equilibrium was established, which could predict the adsorption breakthrough curves of l-Trp well. During the dynamic adsorption process, the pH of mobile phase in the fixed bed changed with changing the l-Trp concentration in the mobile phase. l-Trp was well separated from Na+ and l-Glu with the purity of l-Trp higher than 99%, the recovery rate higher than 95%, and a concentration of 4.69 × 10-3 mol/L. The elution chromatographic peaks of l-Trp, l-Glu, and Na+ and the pH of the outlet solution were predicted satisfactorily.
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Affiliation(s)
- Pengfei Jiao
- . Phone +86-0377-63513605. Fax: +86-0377-63512517
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11
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Jiao P, Zhang X, Wei Y, Meng Y. Adsorption Equilibria, Kinetics, and Column Dynamics of L-Tryptophan on Mixed-Mode Resin HD-1. ACS OMEGA 2022; 7:9614-9621. [PMID: 35350352 PMCID: PMC8945088 DOI: 10.1021/acsomega.1c06960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 02/28/2022] [Indexed: 06/14/2023]
Abstract
The adsorption amount and selectivity of L-tryptophan (l-Trp) on the hydrophobic interaction and ion exchange mixed-mode chromatography medium HD-1 were studied as well as the salt resistance of the resin via adsorption equilibrium experiments. The adsorption mechanisms of l-Trp were illuminated by combining adsorption equilibria and a kinetics analysis. The separation effect was studied by dynamic separation experiments in a fixed-bed. The results indicate that an increase of the concentration proportion of l-Trp zwitterion benefits the adsorption of l-Trp. The resin shows a high adsorption selectivity for l-Trp at different pH values. The adsorption amount of l-Trp is not affected significantly by NaCl. Various groups play a role in the adsorption of l-Trp. An adsorption energy lower than 8 kJ/mol indicates that the adsorption of l-Trp is mainly based on non-electrostatic interactions, with an electrostatic interaction as a supplement. The adsorption equilibrium model considering the dissociation equilibrium of the resin and l-Trp proposed in this work can simulate the adsorption equilibrium data of l-Trp at different pH values as well. The mass transfer rate of l-Trp is controlled by intraparticle and liquid film diffusion simultaneously. The fixed-bed packed with resin HD-1 can separate l-Trp with the purity of l-Trp higher than 99%, recovery rate higher than 95%, and concentration of 4.69 × 10-3 mol/L.
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Affiliation(s)
- Pengfei Jiao
- E-mail: . Phone +86-0377-63513605. Fax: +86-0377-63512517
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Xie X, Ding D, Bai D, Zhu Y, Sun W, Sun Y, Zhang D. Melatonin biosynthesis pathways in nature and its production in engineered microorganisms. Synth Syst Biotechnol 2022; 7:544-553. [PMID: 35087957 PMCID: PMC8761603 DOI: 10.1016/j.synbio.2021.12.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 12/14/2021] [Accepted: 12/24/2021] [Indexed: 12/26/2022] Open
Abstract
Melatonin is a biogenic amine that can be found in plants, animals and microorganism. The metabolic pathway of melatonin is different in various organisms, and biosynthetic endogenous melatonin acts as a molecular signal and antioxidant protection against external stress. Microbial synthesis pathways of melatonin are similar to those of animals but different from those of plants. At present, the method of using microorganism fermentation to produce melatonin is gradually prevailing, and exploring the biosynthetic pathway of melatonin to modify microorganism is becoming the mainstream, which has more advantages than traditional chemical synthesis. Here, we review recent advances in the synthesis, optimization of melatonin pathway. l-tryptophan is one of the two crucial precursors for the synthesis of melatonin, which can be produced through a four-step reaction. Enzymes involved in melatonin synthesis have low specificity and catalytic efficiency. Site-directed mutation, directed evolution or promotion of cofactor synthesis can enhance enzyme activity and increase the metabolic flow to promote microbial melatonin production. On the whole, the status and bottleneck of melatonin biosynthesis can be improved to a higher level, providing an effective reference for future microbial modification.
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Affiliation(s)
- Xiaotong Xie
- Dalian Polytechnic University, Dalian, 116000, PR China
| | - Dongqin Ding
- Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
- Biodesign Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
| | - Danyang Bai
- Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
- Biodesign Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
| | - Yaru Zhu
- Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
- Biodesign Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
| | - Wei Sun
- Tianjin University of science and technology, Tianjin, 300308, PR China
| | - Yumei Sun
- Dalian Polytechnic University, Dalian, 116000, PR China
- Corresponding author.
| | - Dawei Zhang
- Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
- Biodesign Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
- Corresponding author. Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China.
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Zhao X, Zhang Y, Jiang H, Zang H, Wang Y, Sun S, Li C. Efficient vanillin biosynthesis by recombinant lignin-degrading bacterium Arthrobacter sp. C2 and its environmental profile via life cycle assessment. BIORESOURCE TECHNOLOGY 2022; 347:126434. [PMID: 34838969 DOI: 10.1016/j.biortech.2021.126434] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/21/2021] [Accepted: 11/22/2021] [Indexed: 06/13/2023]
Abstract
Vanillin is a natural flavoring agent that is widely used in the bioengineering industry. To enable sustainable development, joint consideration of bacterial performance and negative environmental impacts are critical to vanillin biosynthesis. In this study, a cold shock protein (csp) gene was upregulated for maintaining stable growth in Arthrobacter sp. C2 responding to vanillin and cold stress. Furthermore, the recombinant strain C2 was constructed by simultaneously deleting the xylC gene encoding benzaldehyde dehydrase and overexpressing the pchF gene encoding vanillyl alcohol oxidase and achieved a maximum vanillin productivity of 0.85 mg/g DCW/h with alkaline lignin as the substrate. Finally, this process generated an environmental impact value of 25.05, which was the lowest environmental impact achieved according to life cycle assessment (LCA). Improvement strategies included reducing electricity consumption and replacing chemicals. This study achieved the development of an effective strategy, and future studies should focus on precise vanillin biosynthesis methods for large-scale application.
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Affiliation(s)
- Xinyue Zhao
- College of Resource and Environment, Northeast Agricultural University, Harbin 150030, China
| | - Yuting Zhang
- College of Resource and Environment, Northeast Agricultural University, Harbin 150030, China
| | - Hanyi Jiang
- College of Resource and Environment, Northeast Agricultural University, Harbin 150030, China
| | - Hailian Zang
- College of Resource and Environment, Northeast Agricultural University, Harbin 150030, China
| | - Yue Wang
- College of Resource and Environment, Northeast Agricultural University, Harbin 150030, China
| | - Shanshan Sun
- College of Resource and Environment, Northeast Agricultural University, Harbin 150030, China
| | - Chunyan Li
- College of Resource and Environment, Northeast Agricultural University, Harbin 150030, China.
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Tryptophan Production Maximization in a Fed-Batch Bioreactor with Modified E. coli Cells, by Optimizing Its Operating Policy Based on an Extended Structured Cell Kinetic Model. Bioengineering (Basel) 2021; 8:bioengineering8120210. [PMID: 34940363 PMCID: PMC8698263 DOI: 10.3390/bioengineering8120210] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/04/2021] [Accepted: 12/06/2021] [Indexed: 11/17/2022] Open
Abstract
Hybrid kinetic models, linking structured cell metabolic processes to the dynamics of macroscopic variables of the bioreactor, are more and more used in engineering evaluations to derive more precise predictions of the process dynamics under variable operating conditions. Depending on the cell model complexity, such a math tool can be used to evaluate the metabolic fluxes in relation to the bioreactor operating conditions, thus suggesting ways to genetically modify the microorganism for certain purposes. Even if development of such an extended dynamic model requires more experimental and computational efforts, its use is advantageous. The approached probative example refers to a model simulating the dynamics of nanoscale variables from several pathways of the central carbon metabolism (CCM) of Escherichia coli cells, linked to the macroscopic state variables of a fed-batch bioreactor (FBR) used for the tryptophan (TRP) production. The used E. coli strain was modified to replace the PTS system for glucose (GLC) uptake with a more efficient one. The study presents multiple elements of novelty: (i) the experimentally validated modular model itself, and (ii) its efficiency in computationally deriving an optimal operation policy of the FBR.
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