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Yang Y, Zou Y, Chen X, Sun H, Hua X, Johnston L, Zeng X, Qiao S, Ye C. Metabolic engineering of Escherichia coli for the production of 5-aminolevulinic acid based on combined metabolic pathway modification and reporter-guided mutant selection (RGMS). BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:82. [PMID: 38886801 PMCID: PMC11184883 DOI: 10.1186/s13068-024-02530-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Accepted: 06/10/2024] [Indexed: 06/20/2024]
Abstract
BACKGROUND 5-Aminolevulinic acid (ALA) recently received much attention due to its potential application in many fields such as medicine, nutrition and agriculture. Metabolic engineering is an efficient strategy to improve microbial production of 5-ALA. RESULTS In this study, an ALA production strain of Escherichia coli was constructed by rational metabolic engineering and stepwise improvement. A metabolic strategy to produce ALA directly from glucose in this recombinant E. coli via both C4 and C5 pathways was applied herein. The expression of a modified hemARS gene and rational metabolic engineering by gene knockouts significantly improved ALA production from 765.9 to 2056.1 mg/L. Next, we tried to improve ALA production by RGMS-directed evolution of eamA gene. After RGMS, the ALA yield of strain A2-ASK reached 2471.3 mg/L in flask. Then, we aimed to improve the oxidation resistance of cells by overexpressing sodB and katE genes and ALA yield reached 2703.8 mg/L. A final attempt is to replace original promoter of hemB gene in genome with a weaker one to decrease its expression. After 24 h cultivation, a high ALA yield of 19.02 g/L was achieved by 108-ASK in a 5 L fermenter. CONCLUSIONS These results suggested that an industrially competitive strain can be efficiently developed by metabolic engineering based on combined rational modification and optimization of gene expression.
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Affiliation(s)
- Yuting Yang
- State Key Laboratory of Animal Nutrition and Feeding, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing, 100193, China
- Beijing Key Laboratory of Bio-Feed Additives, Beijing, 100193, China
| | - Yuhong Zou
- State Key Laboratory of Animal Nutrition and Feeding, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing, 100193, China
- Beijing Key Laboratory of Bio-Feed Additives, Beijing, 100193, China
| | - Xi Chen
- State Key Laboratory for Agro-Biotechnology, Ministry of Agriculture and Rural Affairs, Key Laboratory for Pest Monitoring and Green Management, Department of Plant Pathology, China Agricultural University, Beijing, 100193, China
| | - Haidong Sun
- National Feed Engineering Technology Research Centre, Beijing, 100193, China
| | - Xia Hua
- State Key Laboratory for Agro-Biotechnology, Ministry of Agriculture and Rural Affairs, Key Laboratory for Pest Monitoring and Green Management, Department of Plant Pathology, China Agricultural University, Beijing, 100193, China
| | - Lee Johnston
- Swine Nutrition and Production, West Central Research and Outreach Center, University of Minnesota, Morris, MN, 56267, USA
| | - Xiangfang Zeng
- State Key Laboratory of Animal Nutrition and Feeding, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing, 100193, China
- Beijing Key Laboratory of Bio-Feed Additives, Beijing, 100193, China
| | - Shiyan Qiao
- State Key Laboratory of Animal Nutrition and Feeding, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing, 100193, China
- Beijing Key Laboratory of Bio-Feed Additives, Beijing, 100193, China
| | - Changchuan Ye
- State Key Laboratory of Animal Nutrition and Feeding, Ministry of Agriculture Feed Industry Centre, China Agricultural University, Beijing, 100193, China.
- Department of Animal Science, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
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2
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Frick-Cheng AE, Shea AE, Roberts JR, Smith SN, Ohi MD, Mobley HLT. Iron limitation induces motility in uropathogenic E. coli CFT073 partially through action of LpdA. mBio 2024:e0104824. [PMID: 38874412 DOI: 10.1128/mbio.01048-24] [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: 04/11/2024] [Accepted: 05/07/2024] [Indexed: 06/15/2024] Open
Abstract
More than half of women will experience a urinary tract infection (UTI) with most cases caused by uropathogenic Escherichia coli (UPEC). Bacterial swimming motility enhances UPEC pathogenicity, resulting in more severe disease outcomes including kidney infection. Surprisingly, the connection between motility and iron limitation is mostly unexplored despite the lack of free iron available in the host. We sought to investigate a potential connection between iron restriction and regulation of motility in UPEC. We cultured E. coli CFT073, a prototypical UPEC strain, under iron limitation and observed that CFT073 had elevated fliC (flagella) promoter activity, and this iron-specific response was repressed by the addition of exogenous iron. We confirmed increased flagellar expression in CFT073 by measuring fliC transcript, FliC protein, and surface-expressed flagella under iron-limited conditions. Interestingly, known motility regulator flhDC did not have altered transcription under these conditions. To define the regulatory mechanism of this response, we constructed single knockouts of eight master regulators and found the iron-regulated response was lost in crp, arcA, and fis mutants. Thus, we focused on the five genes regulated by all three regulators. Of the five genes knocked out, the iron-regulated motility response was most strongly dysregulated in the lpdA mutant, which also resulted in significantly lowered fitness in the murine model of ascending UTI, both against the WT and a non-motile fliC mutant. Collectively, we demonstrated that iron-mediated motility in CFT073 is partially regulated by lpdA, which contributes to the understanding of how uropathogens differentially regulate motility mechanisms in the iron-restricted host. IMPORTANCE Urinary tract infections (UTIs) are ubiquitous and responsible for over five billion dollars in associated health care costs annually. Both iron acquisition and motility are highly studied virulence factors associated with uropathogenic Escherichia coli (UPEC), the main causative agent of uncomplicated UTI. This work is innovative by providing mechanistic insight into the synergistic relationship between these two critical virulence properties. Here, we demonstrate that iron limitation has pleiotropic effects with consequences that extend beyond metabolism and impact other virulence mechanisms. Indeed, targeting iron acquisition as a therapy may lead to an undesirable enhancement of UPEC pathogenesis through increased motility. It is vital to understand the full breadth of UPEC pathogenesis to adequately respond to this common infection, especially with the increase of antibiotic-resistant pathogens.
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Affiliation(s)
- A E Frick-Cheng
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - A E Shea
- Department of Microbiology and Immunology, University of South Alabama Medical School, Mobile, Alabama, USA
| | - J R Roberts
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - S N Smith
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - M D Ohi
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - H L T Mobley
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
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3
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Li XD, Jiang GF, Li R, Bai Y, Zhang GS, Xu SJ, Deng WA. Molecular strategies of the pygmy grasshopper Eucriotettix oculatus adapting to long-term heavy metal pollution. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 276:116301. [PMID: 38599159 DOI: 10.1016/j.ecoenv.2024.116301] [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: 08/21/2023] [Revised: 03/31/2024] [Accepted: 04/03/2024] [Indexed: 04/12/2024]
Abstract
To study the heavy metal accumulation and its impact on insect exterior and chromosome morphology, and reveal the molecular mechanism of insects adapting to long-term heavy metal compound pollution habitats, this study, in the Diaojiang river basin, which has been polluted by heavy metals(HMs) for nearly a thousand years, two Eucriotettix oculatus populations was collected from mining and non-mining areas. It was found that the contents of 7 heavy metals (As, Cd, Pb, Zn, Cu, Sn, Sb) in E. oculatus of the mining area were higher than that in the non-mining 1-11 times. The analysis of morphology shows that the external morphology, the hind wing type and the chromosomal morphology of E. oculatus are significant differences between the two populations. Based on the heavy metal accumulation,morphological change, and stable population density, it is inferred that the mining area population has been affected by heavy metals and has adapted to the environment of heavy metals pollution. Then, by analyzing the transcriptome of the two populations, it was found that the digestion, immunity, excretion, endocrine, nerve, circulation, reproductive and other systems and lysosomes, endoplasmic reticulum and other cell structure-related gene expression were suppressed. This shows that the functions of the above-mentioned related systems of E. oculatus are inhibited by heavy metal stress. However, it has also been found that through the significant up-regulation of genes related to the above system, such as ATP2B, pepsin A, ubiquitin, AQP1, ACOX, ATPeV0A, SEC61A, CANX, ALDH7A1, DLD, aceE, Hsp40, and catalase, etc., and the down-regulation of MAPK signalling pathway genes, can enhanced nutrient absorption, improve energy metabolism, repair damaged cells and degrade abnormal proteins, maintain the stability of cells and systems, and resist heavy metal damage so that E. oculatus can adapt to the environment of heavy metal pollution for a long time.
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Affiliation(s)
- Xiao-Dong Li
- Guangxi Key Laboratory of Sericulture Ecology and Applied Intelligent Technology, School of Chemistry and Bioengineering, Hechi University Yizhou 546300, China; Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210000, China
| | - Guo-Fang Jiang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210000, China; College of Oceanology and Food Sciences, Quanzhou Normal University, Quanzhou 362000, China.
| | - Ran Li
- School of Life Sciences, Qufu Normal University, Qufu 273165, China
| | - Yi Bai
- School of Life Science, Taizhou University, Taizhou 317000, China
| | - Guo-Song Zhang
- School of Agriculture and Bioengineering, Heze University, Heze 274000, China
| | - Shu-Juan Xu
- College of Life Science and Technology, Longdong University, Qingyang 745000, China
| | - Wei-An Deng
- Guangxi Key Laboratory of Sericulture Ecology and Applied Intelligent Technology, School of Chemistry and Bioengineering, Hechi University Yizhou 546300, China; College of Life Science, Guangxi Normal University, Guilin 541004, China.
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Soria S, Carreón-Rodríguez OE, de Anda R, Flores N, Escalante A, Bolívar F. Transcriptional and Metabolic Response of a Strain of Escherichia coli PTS - to a Perturbation of the Energetic Level by Modification of [ATP]/[ADP] Ratio. BIOTECH 2024; 13:10. [PMID: 38651490 PMCID: PMC11036233 DOI: 10.3390/biotech13020010] [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: 03/13/2024] [Revised: 04/06/2024] [Accepted: 04/08/2024] [Indexed: 04/25/2024] Open
Abstract
The intracellular [ATP]/[ADP] ratio is crucial for Escherichia coli's cellular functions, impacting transport, phosphorylation, signaling, and stress responses. Overexpression of F1-ATPase genes in E. coli increases glucose consumption, lowers energy levels, and triggers transcriptional responses in central carbon metabolism genes, particularly glycolytic ones, enhancing carbon flux. In this contribution, we report the impact of the perturbation of the energetic level in a PTS- mutant of E. coli by modifying the [ATP]/[ADP] ratio by uncoupling the cytoplasmic activity of the F1 subunit of the ATP synthase. The disruption of [ATP]/[ADP] ratio in the evolved strain of E. coli PB12 (PTS-) was achieved by the expression of the atpAGD operon encoding the soluble portion of ATP synthase F1-ATPase (strain PB12AGD+). The analysis of the physiological and metabolic response of the PTS- strain to the ATP disruption was determined using RT-qPCR of 96 genes involved in glucose and acetate transport, glycolysis and gluconeogenesis, pentose phosphate pathway (PPP), TCA cycle and glyoxylate shunt, several anaplerotic, respiratory chain, and fermentative pathways genes, sigma factors, and global regulators. The apt mutant exhibited reduced growth despite increased glucose transport due to decreased energy levels. It heightened stress response capabilities under glucose-induced energetic starvation, suggesting that the carbon flux from glycolysis is distributed toward the pentose phosphate and the Entner-Duodoroff pathway with the concomitant. Increase acetate transport, production, and utilization in response to the reduction in the [ATP]/[ADP] ratio. Upregulation of several genes encoding the TCA cycle and the glyoxylate shunt as several respiratory genes indicates increased respiratory capabilities, coupled possibly with increased availability of electron donor compounds from the TCA cycle, as this mutant increased respiratory capability by 240% more than in the PB12. The reduction in the intracellular concentration of cAMP in the atp mutant resulted in a reduced number of upregulated genes compared to PB12, suggesting that the mutant remains a robust genetic background despite the severe disruption in its energetic level.
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Affiliation(s)
- Sandra Soria
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca 62210, Mexico; (S.S.); (O.E.C.-R.); (R.d.A.); (N.F.)
- Laboratorio de Soluciones Biotecnológicas (LasoBiotc), Montevideo 11800, Uruguay
| | - Ofelia E. Carreón-Rodríguez
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca 62210, Mexico; (S.S.); (O.E.C.-R.); (R.d.A.); (N.F.)
| | - Ramón de Anda
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca 62210, Mexico; (S.S.); (O.E.C.-R.); (R.d.A.); (N.F.)
| | - Noemí Flores
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca 62210, Mexico; (S.S.); (O.E.C.-R.); (R.d.A.); (N.F.)
| | - Adelfo Escalante
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca 62210, Mexico; (S.S.); (O.E.C.-R.); (R.d.A.); (N.F.)
| | - Francisco Bolívar
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca 62210, Mexico; (S.S.); (O.E.C.-R.); (R.d.A.); (N.F.)
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5
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Huening KA, Groves JT, Wildenthal JA, Tabita FR, North JA. Escherichia coli possessing the dihydroxyacetone phosphate shunt utilize 5'-deoxynucleosides for growth. Microbiol Spectr 2024; 12:e0308623. [PMID: 38441472 PMCID: PMC10986504 DOI: 10.1128/spectrum.03086-23] [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: 08/12/2023] [Accepted: 02/17/2024] [Indexed: 03/08/2024] Open
Abstract
All organisms utilize S-adenosyl-l-methionine (SAM) as a key co-substrate for the methylation of biological molecules, the synthesis of polyamines, and radical SAM reactions. When these processes occur, 5'-deoxy-nucleosides are formed as byproducts such as S-adenosyl-l-homocysteine, 5'-methylthioadenosine (MTA), and 5'-deoxyadenosine (5dAdo). A prevalent pathway found in bacteria for the metabolism of MTA and 5dAdo is the dihydroxyacetone phosphate (DHAP) shunt, which converts these compounds into dihydroxyacetone phosphate and 2-methylthioacetaldehyde or acetaldehyde, respectively. Previous work in other organisms has shown that the DHAP shunt can enable methionine synthesis from MTA or serve as an MTA and 5dAdo detoxification pathway. Rather, the DHAP shunt in Escherichia coli ATCC 25922, when introduced into E. coli K-12, enables the use of 5dAdo and MTA as a carbon source for growth. When MTA is the substrate, the sulfur component is not significantly recycled back to methionine but rather accumulates as 2-methylthioethanol, which is slowly oxidized non-enzymatically under aerobic conditions. The DHAP shunt in ATCC 25922 is active under oxic and anoxic conditions. Growth using 5-deoxy-d-ribose was observed during aerobic respiration and anaerobic respiration with Trimethylamine N-oxide (TMAO), but not during fermentation or respiration with nitrate. This suggests the DHAP shunt may only be relevant for extraintestinal pathogenic E. coli lineages with the DHAP shunt that inhabit oxic or TMAO-rich extraintestinal environments. This reveals a heretofore overlooked role of the DHAP shunt in carbon and energy metabolism from ubiquitous SAM utilization byproducts and suggests a similar role may occur in other pathogenic and non-pathogenic bacteria with the DHAP shunt. IMPORTANCE The acquisition and utilization of organic compounds that serve as growth substrates are essential for Escherichia coli to grow and multiply. Ubiquitous enzymatic reactions involving S-adenosyl-l-methionine as a co-substrate by all organisms result in the formation of the 5'-deoxy-nucleoside byproducts, 5'-methylthioadenosine and 5'-deoxyadenosine. All E. coli possess a conserved nucleosidase that cleaves these 5'-deoxy-nucleosides into 5-deoxy-pentose sugars for adenine salvage. The DHAP shunt pathway is found in some extraintestinal pathogenic E. coli, but its function in E. coli possessing it has remained unknown. This study reveals that the DHAP shunt enables the utilization of 5'-deoxy-nucleosides and 5-deoxy-pentose sugars as growth substrates in E. coli strains with the pathway during aerobic respiration and anaerobic respiration with TMAO, but not fermentative growth. This provides an insight into the diversity of sugar compounds accessible by E. coli with the DHAP shunt and suggests that the DHAP shunt is primarily relevant in oxic or TMAO-rich extraintestinal environments.
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Affiliation(s)
| | - Joshua T. Groves
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - John A. Wildenthal
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - F. Robert Tabita
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - Justin A. North
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
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6
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Frick-Cheng AE, Shea AE, Roberts JR, Smith SN, Ohi MD, Mobley HLT. Altered motility in response to iron-limitation is regulated by lpdA in uropathogenic E. coli CFT073. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.27.559868. [PMID: 37808639 PMCID: PMC10557643 DOI: 10.1101/2023.09.27.559868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
More than half of all women will experience a urinary tract infection (UTI) in their lifetime with most cases caused by uropathogenic Escherichia coli (UPEC). Bacterial motility enhances UPEC pathogenicity, resulting in more severe disease outcomes including kidney infection. Surprisingly, the connection between motility and iron limitation is mostly unexplored, despite the lack of free iron available in the host. Therefore, we sought to explore the potential connection between iron restriction and regulation of motility in UPEC. We cultured E. coli CFT073, a prototypical UPEC strain, in media containing an iron chelator. Under iron limitation, CFT073 had elevated fliC (flagella) promoter activity, driving motility on the leading edge of the colony. Furthermore, this iron-specific response was repressed by the addition of exogenous iron. We confirmed increased flagella expression in CFT073 by measuring fliC transcript, FliC protein, and surface-expressed flagella under iron-limited conditions. To define the regulatory mechanism, we constructed single knockouts of eight master regulators. The iron-regulated response was lost in crp, arcA, and fis mutants. Thus, we focused on the five genes regulated by all three transcription factors. Of the five genes knocked out, the iron-regulated motility response was most strongly dysregulated in an lpdA mutant, which also resulted in significantly lowered fitness in the murine model of ascending UTI. Collectively, we demonstrated that iron-mediated motility in CFT073 is regulated by lpdA , which contributes to the understanding of how uropathogens differentially regulate motility mechanisms in the iron-restricted host. Importance Urinary tract infections (UTIs) are ubiquitous and responsible for over five billion dollars in associated health care costs annually. Both iron acquisition and motility are highly studied virulence factors associated with uropathogenic E. coli (UPEC), the main causative agent of uncomplicated UTI. This work is innovative by providing mechanistic insight into the synergistic relationship between these two critical virulence properties. Here, we demonstrate that iron limitation has pleiotropic effects with consequences that extend beyond metabolism, and impact other virulence mechanisms. Indeed, targeting iron acquisition as a therapy may lead to an undesirable enhancement of UPEC pathogenesis through increased motility. It is vital to understand the full breadth of UPEC pathogenesis to adequately respond to this common infection, especially with the increase of antibiotic resistant pathogens.
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7
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Huening KA, Groves JT, Wildenthal JA, Tabita FR, North JA. Utilization of 5'-deoxy-nucleosides as Growth Substrates by Extraintestinal Pathogenic E. coli via the Dihydroxyacetone Phosphate Shunt. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.10.552779. [PMID: 37609188 PMCID: PMC10441430 DOI: 10.1101/2023.08.10.552779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
All organisms utilize S-adenosyl-l-methionine (SAM) as a key co-substrate for methylation of biological molecules, synthesis of polyamines, and radical SAM reactions. When these processes occur, 5'-deoxy-nucleosides are formed as byproducts such as S-adenosyl-l-homocysteine (SAH), 5'-methylthioadenosine (MTA), and 5'-deoxyadenosine (5dAdo). One of the most prevalent pathways found in bacteria for the metabolism of MTA and 5dAdo is the DHAP shunt, which converts these compounds into dihydroxyacetone phosphate (DHAP) and 2-methylthioacetaldehyde or acetaldehyde, respectively. Previous work has shown that the DHAP shunt can enable methionine synthesis from MTA or serve as an MTA and 5dAdo detoxification pathway. Here we show that in Extraintestinal Pathogenic E. coil (ExPEC), the DHAP shunt serves none of these roles in any significant capacity, but rather physiologically functions as an assimilation pathway for use of MTA and 5dAdo as growth substrates. This is further supported by the observation that when MTA is the substrate for the ExPEC DHAP shunt, the sulfur components is not significantly recycled back to methionine, but rather accumulates as 2-methylthioethanol, which is slowly oxidized non-enzymatically under aerobic conditions. While the pathway is active both aerobically and anaerobically, it only supports aerobic ExPEC growth, suggesting that it primarily functions in oxygenic extraintestinal environments like blood and urine versus the predominantly anoxic gut. This reveals a heretofore overlooked role of the DHAP shunt in carbon assimilation and energy metabolism from ubiquitous SAM utilization byproducts and suggests a similar role may occur in other pathogenic and non-pathogenic bacteria with the DHAP shunt.
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Affiliation(s)
| | - Joshua T. Groves
- The Ohio State University Department of Microbiology, Columbus, OH, 43210
| | - John A. Wildenthal
- The Ohio State University Department of Microbiology, Columbus, OH, 43210
| | - F. Robert Tabita
- The Ohio State University Department of Microbiology, Columbus, OH, 43210
| | - Justin A. North
- The Ohio State University Department of Microbiology, Columbus, OH, 43210
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8
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Sousa FM, Fernandes B, Pereira MM. The protein family of pyruvate:quinone oxidoreductases: Amino acid sequence conservation and taxonomic distribution. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148958. [PMID: 36758662 DOI: 10.1016/j.bbabio.2023.148958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 12/24/2022] [Accepted: 02/01/2023] [Indexed: 02/11/2023]
Abstract
Pyruvate:quinone oxidoreductases (PQOs) catalyse the oxidative decarboxylation of pyruvate to acetate and concomitant reduction of quinone to quinol with the release of CO2. They are thiamine pyrophosphate (TPP) and flavin-adenine dinucleotide (FAD) containing enzymes, which interact with the membrane in a monotopic way. PQOs are considered as part of alternatives to most recognized pyruvate catabolizing pathways, and little is known about their taxonomic distribution and structural/functional relationship. In this bioinformatics work we tackled these gaps in PQO knowledge. We used the KEGG database to identify PQO coding genes, performed a multiple sequence analysis which allowed us to study the amino acid conservation on these enzymes, and looked at their possible cellular function. We observed that PQOS are enzymes exclusively present in prokaryotes with most of the sequences identified in bacteria. Regarding the amino acid sequence conservation, we found that 75 amino acid residues (out of 570, on average) have a conservation over 90 %, and that the most conserved regions in the protein are observed around the TPP and FAD binding sites. We systematized the presence of conserved features involved in Mg2+, TPP and FAD binding, as well as residues directly linked to the catalytic mechanism. We also established the presence of a new motif named "HEH lock", possibly involved in the dimerization process. The results here obtained for the PQO protein family contribute to a better understanding of the biochemistry of these respiratory enzymes.
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Affiliation(s)
- Filipe M Sousa
- Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157 Oeiras, Portugal; BioISI-Biosystems & Integrative Sciences Institute and Department of Chemistry and Biochemistry, Faculty of Sciences, University of Lisboa, 1749-016 Lisboa, Portugal
| | - Bárbara Fernandes
- Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157 Oeiras, Portugal; BioISI-Biosystems & Integrative Sciences Institute and Department of Chemistry and Biochemistry, Faculty of Sciences, University of Lisboa, 1749-016 Lisboa, Portugal
| | - Manuela M Pereira
- Instituto de Tecnologia Química e Biológica-António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157 Oeiras, Portugal; BioISI-Biosystems & Integrative Sciences Institute and Department of Chemistry and Biochemistry, Faculty of Sciences, University of Lisboa, 1749-016 Lisboa, Portugal.
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9
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The Production of Pyruvate in Biological Technology: A Critical Review. Microorganisms 2022; 10:microorganisms10122454. [PMID: 36557706 PMCID: PMC9783380 DOI: 10.3390/microorganisms10122454] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/06/2022] [Accepted: 12/10/2022] [Indexed: 12/14/2022] Open
Abstract
Pyruvic acid has numerous applications in the food, chemical, and pharmaceutical industries. The high costs of chemical synthesis have prevented the extensive use of pyruvate for many applications. Metabolic engineering and traditional strategies for mutation and selection have been applied to microorganisms to enhance their ability to produce pyruvate. In the past decades, different microbial strains were generated to enhance their pyruvate production capability. In addition to the development of genetic engineering and metabolic engineering in recent years, the metabolic transformation of wild-type yeast, E. coli, and so on to produce high-yielding pyruvate strains has become a hot spot. The strategy and the understanding of the central metabolism directly related to pyruvate production could provide valuable information for improvements in fermentation products. One of the goals of this review was to collect information regarding metabolically engineered strains and the microbial fermentation processes used to produce pyruvate in high yield and productivity.
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10
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Ketcham A, Freddolino PL, Tavazoie S. Intracellular acidification is a hallmark of thymineless death in E. coli. PLoS Genet 2022; 18:e1010456. [PMID: 36279294 PMCID: PMC9632930 DOI: 10.1371/journal.pgen.1010456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 11/03/2022] [Accepted: 10/01/2022] [Indexed: 11/05/2022] Open
Abstract
Thymidine starvation causes rapid cell death. This enigmatic process known as thymineless death (TLD) is the underlying killing mechanism of diverse antimicrobial and antineoplastic drugs. Despite decades of investigation, we still lack a mechanistic understanding of the causal sequence of events that culminate in TLD. Here, we used a diverse set of unbiased approaches to systematically determine the genetic and regulatory underpinnings of TLD in Escherichia coli. In addition to discovering novel genes in previously implicated pathways, our studies revealed a critical and previously unknown role for intracellular acidification in TLD. We observed that a decrease in cytoplasmic pH is a robust early event in TLD across different genetic backgrounds. Furthermore, we show that acidification is a causal event in the death process, as chemical and genetic perturbations that increase intracellular pH substantially reduce killing. We also observe a decrease in intracellular pH in response to exposure to the antibiotic gentamicin, suggesting that intracellular acidification may be a common mechanistic step in the bactericidal effects of other antibiotics.
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Affiliation(s)
- Alexandra Ketcham
- Department of Biological Sciences, Columbia University, New York, New York, United States of America
- Department of Systems Biology, Columbia University, New York, New York, United States of America
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York, United States of America
| | - Peter L. Freddolino
- Department of Systems Biology, Columbia University, New York, New York, United States of America
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York, United States of America
| | - Saeed Tavazoie
- Department of Biological Sciences, Columbia University, New York, New York, United States of America
- Department of Systems Biology, Columbia University, New York, New York, United States of America
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York, United States of America
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11
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Liu X, Zhao G, Sun S, Fan C, Feng X, Xiong P. Biosynthetic Pathway and Metabolic Engineering of Succinic Acid. Front Bioeng Biotechnol 2022; 10:843887. [PMID: 35350186 PMCID: PMC8957974 DOI: 10.3389/fbioe.2022.843887] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 02/16/2022] [Indexed: 11/25/2022] Open
Abstract
Succinic acid, a dicarboxylic acid produced as an intermediate of the tricarboxylic acid (TCA) cycle, is one of the most important platform chemicals for the production of various high value-added derivatives. As traditional chemical synthesis processes suffer from nonrenewable resources and environment pollution, succinic acid biosynthesis has drawn increasing attention as a viable, more environmentally friendly alternative. To date, several metabolic engineering approaches have been utilized for constructing and optimizing succinic acid cell factories. In this review, different succinic acid biosynthesis pathways are summarized, with a focus on the key enzymes and metabolic engineering approaches, which mainly include redirecting carbon flux, balancing NADH/NAD+ ratios, and optimizing CO2 supplementation. Finally, future perspectives on the microbial production of succinic acid are discussed.
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Affiliation(s)
- Xiutao Liu
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
| | - Guang Zhao
- State Key Lab of Microbial Technology, Shandong University, Qingdao, China
| | - Shengjie Sun
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
| | - Chuanle Fan
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.,School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Xinjun Feng
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Peng Xiong
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
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12
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Shi LL, Zheng Y, Tan BW, Li ZJ. Establishment of a carbon-efficient xylulose cleavage pathway in Escherichia coli to metabolize xylose. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2021.108331] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Liu S, Xu JZ, Zhang WG. Advances and prospects in metabolic engineering of Escherichia coli for L-tryptophan production. World J Microbiol Biotechnol 2022; 38:22. [PMID: 34989926 DOI: 10.1007/s11274-021-03212-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 12/15/2021] [Indexed: 10/19/2022]
Abstract
As an important raw material for pharmaceutical, food and feed industry, highly efficient production of L-tryptophan by Escherichia coli has attracted a considerable attention. However, there are complicated and multiple layers of regulation networks in L-tryptophan biosynthetic pathway and thus have difficulty to rewrite the biosynthetic pathway for producing L-tryptophan with high efficiency in E. coli. This review summarizes the biosynthetic pathway of L-tryptophan and highlights the main regulatory mechanisms in E. coli. In addition, we discussed the latest metabolic engineering strategies achieved in E. coli to reconstruct the L-tryptophan biosynthetic pathway. Moreover, we also review a few strategies that can be used in E. coli to improve robustness and streamline of L-tryptophan high-producing strains. Lastly, we also propose the potential strategies to further increase L-tryptophan production by systematic metabolic engineering and synthetic biology techniques.
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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, People's Republic of China
| | - Jian-Zhong Xu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800# Lihu Road, WuXi, 214122, People's Republic of China.
| | - Wei-Guo Zhang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800# Lihu Road, WuXi, 214122, People's Republic of China.
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14
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Mieszkin S, Pouder E, Uroz S, Simon-Colin C, Alain K. Acidisoma silvae sp. nov. and Acidisomacellulosilytica sp. nov., Two Acidophilic Bacteria Isolated from Decaying Wood, Hydrolyzing Cellulose and Producing Poly-3-hydroxybutyrate. Microorganisms 2021; 9:microorganisms9102053. [PMID: 34683374 PMCID: PMC8537097 DOI: 10.3390/microorganisms9102053] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 09/17/2021] [Accepted: 09/25/2021] [Indexed: 12/02/2022] Open
Abstract
Two novel strains, HW T2.11T and HW T5.17T, were isolated from decaying wood (forest of Champenoux, France). Study of the 16S rRNA sequence similarity indicated that the novel strains belong to the genus Acidisoma. The sequence similarity of the 16S rRNA gene of HW T2.11T with the corresponding sequences of A. tundrae and A. sibiricum was 97.30% and 97.25%, while for HW T5.17T it was 96.85% and 97.14%, respectively. The DNA G+C contents of the strains were 62.32–62.50%. Cells were Gram-negative coccobacilli that had intracellular storage granules (poly-3-hydroxybutyrate (P3HB)) that confer resistance to environmental stress conditions. They were mesophilic and acidophilic organisms growing at 8–25 °C, at a pH of 2.0–6.5, and were capable of using a wide range of organic compounds and complex biopolymers such as starch, fucoidan, laminarin, pectin and cellulose, the latter two being involved in wood composition. The major cellular fatty acid was cyclo C19:0ω8c and the major quinone was Q-10. Overall, genome relatedness indices between genomes of strains HW T2.11T and HW T5.17T (Orthologous Average Nucleotide Identity (OrthoANI) value = 83.73% and digital DNA-DNA hybridization score = 27.5%) confirmed that they belonged to two different species. Genetic predictions indicate that the cyclopropane fatty acid (CFA) pathway is present, conferring acid-resistance properties to the cells. The two novel strains might possess a class IV polyhydroxyalcanoate (PHA) synthase operon involved in the P3HB production pathway. Overall, the polyphasic taxonomic analysis shows that these two novel strains are adapted to harsh environments such as decaying wood where the organic matter is difficult to access, and can contribute to the degradation of dead wood. These strains represent novel species of the genus Acidisoma, for which the names Acidisoma silvae sp. nov. and Acidisomacellulosilytica sp. nov. are proposed. The type strains of Acidisoma silvae and Acidisomacellulosilytica are, respectively, HW T2.11T (DSM 111006T; UBOCC-M-3364T) and HW T5.17T (DSM 111007T; UBOCC-M-3365T).
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Affiliation(s)
- Sophie Mieszkin
- Laboratoire de Microbiologie des Environnements Extrêmes LM2E, Université de Brest, CNRS, Ifremer, IUEM, Rue Dumont d’Urville, F-29280 Plouzané, France; (E.P.); (C.S.-C.); (K.A.)
- Centre INRAE-Grand Est-Nancy, Université de Lorraine, INRAE, UMR IAM, 54280 Champenoux, F-54000 Nancy, France;
- Correspondence:
| | - Eva Pouder
- Laboratoire de Microbiologie des Environnements Extrêmes LM2E, Université de Brest, CNRS, Ifremer, IUEM, Rue Dumont d’Urville, F-29280 Plouzané, France; (E.P.); (C.S.-C.); (K.A.)
| | - Stéphane Uroz
- Centre INRAE-Grand Est-Nancy, Université de Lorraine, INRAE, UMR IAM, 54280 Champenoux, F-54000 Nancy, France;
| | - Christelle Simon-Colin
- Laboratoire de Microbiologie des Environnements Extrêmes LM2E, Université de Brest, CNRS, Ifremer, IUEM, Rue Dumont d’Urville, F-29280 Plouzané, France; (E.P.); (C.S.-C.); (K.A.)
| | - Karine Alain
- Laboratoire de Microbiologie des Environnements Extrêmes LM2E, Université de Brest, CNRS, Ifremer, IUEM, Rue Dumont d’Urville, F-29280 Plouzané, France; (E.P.); (C.S.-C.); (K.A.)
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15
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Large metabolic rewiring from small genomic changes between strains of Shigella flexneri. J Bacteriol 2021; 203:JB.00056-21. [PMID: 33753469 PMCID: PMC8117524 DOI: 10.1128/jb.00056-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The instability of Shigella genomes has been described, but how this instability causes phenotypic differences within the Shigella flexneri species is largely unknown and likely variable. We describe herein the genome of S. flexneri strain PE577, originally a clinical isolate, which exhibits several phenotypic differences compared to the model strain 2457T. Like many previously described strains of S. flexneri, PE577 lacks discernible, functional CRISPR and restriction-modification systems. Its phenotypic differences when compared to 2457T include lower transformation efficiency, higher oxygen sensitivity, altered carbon metabolism, and greater susceptibility to a wide variety of lytic bacteriophage isolates. Since relatively few Shigella phages have been isolated on 2457T or the previously characterized strain M90T, developing a more universal model strain for isolating and studying Shigella phages is critical to understanding both phages and phage-host interactions. In addition to phage biology, the genome sequence of PE577 was used to generate and test hypotheses of how pseudogenes in this strain-whether interrupted by degraded prophages, transposases, frameshifts, or point mutations-have led to metabolic rewiring compared to the model strain 2457T. Results indicate that PE577 can utilise the less-efficient pyruvate oxidase/acetyl-CoA synthetase (PoxB/Acs) pathway to produce acetyl-CoA, while strain 2457T cannot due to a nonsense mutation in acs, rendering it a pseudogene in this strain. Both strains also utilize pyruvate-formate lyase to oxidize formate but cannot survive with this pathway alone, possibly because a component of the formate-hydrogen lyase (fdhF) is a pseudogene in both strains.Importance Shigella causes millions of dysentery cases worldwide, primarily affecting children under five years old. Despite active research in developing vaccines and new antibiotics, relatively little is known about the variation of physiology or metabolism across multiple isolates. In this work, we investigate two strains of S. flexneri that share 98.9% genetic identity but exhibit drastic differences in metabolism, ultimately affecting the growth of the two strains. Results suggest additional strains within the S. flexneri species utilize different metabolic pathways to process pyruvate. Metabolic differences between these closely-related isolates suggest an even wider variety of differences in growth across S. flexneri and Shigella in general. Exploring this variation further may assist the development or application of vaccines and therapeutics to combat Shigella infections.
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16
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Kim Y, Lama S, Agrawal D, Kumar V, Park S. Acetate as a potential feedstock for the production of value-added chemicals: Metabolism and applications. Biotechnol Adv 2021; 49:107736. [PMID: 33781888 DOI: 10.1016/j.biotechadv.2021.107736] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 02/22/2021] [Accepted: 03/19/2021] [Indexed: 10/21/2022]
Abstract
Acetate is regarded as a promising carbon feedstock in biological production owing to its possible derivation from C1 gases such as CO, CO2 and methane. To best use of acetate, comprehensive understanding of acetate metabolisms from genes and enzymes to pathways and regulations is needed. This review aims to provide an overview on the potential of acetate as carbon feedstock for industrial biotechnology. Biochemical, microbial and biotechnological aspects of acetate metabolism are described. Especially, the current state-of-the art in the production of value-added chemicals from acetate is summarized. Challenges and future perspectives are also provided.
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Affiliation(s)
- Yeonhee Kim
- School of Energy and Chemical Engineering, UNIST, 50, UNIST-gil, Ulsan 44919, Republic of Korea
| | - Suman Lama
- School of Energy and Chemical Engineering, UNIST, 50, UNIST-gil, Ulsan 44919, Republic of Korea
| | - Deepti Agrawal
- Biochemistry and Biotechnology Area, Material Resource Efficiency Division, CSIR- Indian Institute of Petroleum, Mohkampur, Dehradun 248005, India
| | - Vinod Kumar
- Centre for Climate and Environmental Protection, School of Water, Energy and Environment, Cranfield University, Cranfield, MK430AL, United Kingdom.
| | - Sunghoon Park
- School of Energy and Chemical Engineering, UNIST, 50, UNIST-gil, Ulsan 44919, Republic of Korea.
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17
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Fang Y, Zhang S, Wang J, Yin L, Zhang H, Wang Z, Song J, Hu X, Wang X. Metabolic Detoxification of 2-Oxobutyrate by Remodeling Escherichia coli Acetate Bypass. Metabolites 2021; 11:metabo11010030. [PMID: 33406667 PMCID: PMC7824062 DOI: 10.3390/metabo11010030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/22/2020] [Accepted: 12/28/2020] [Indexed: 12/03/2022] Open
Abstract
2-Oxobutyrate (2-OBA), as a toxic metabolic intermediate, generally arrests the cell growth of most microorganisms and blocks the biosynthesis of target metabolites. In this study, we demonstrated that using the acetate bypass to replace the pyruvate dehydrogenase complex (PDHc) in Escherichia coli could recharge the intracellular acetyl-CoA pool to alleviate the metabolic toxicity of 2-OBA. Furthermore, based on the crystal structure of pyruvate oxidase (PoxB), two candidate residues in the substrate-binding pocket of PoxB were predicted by computational simulation. Site-directed saturation mutagenesis was performed to attenuate 2-OBA-binding affinity, and one of the variants, PoxBF112W, exhibited a 20-fold activity ratio of pyruvate/2-OBA in substrate selectivity. PoxBF112W was employed to remodel the acetate bypass in E. coli, resulting in l-threonine (a precursor of 2-OBA) biosynthesis with minimal inhibition from 2-OBA. After metabolic detoxification of 2-OBA, the supplies of intracellular acetyl-CoA and NADPH (nicotinamide adenine dinucleotide phosphate) used for l-threonine biosynthesis were restored. Therefore, 2-OBA is the substitute for pyruvate to engage in enzymatic reactions and disturbs pyruvate metabolism. Our study makes a straightforward explanation of the 2-OBA toxicity mechanism and gives an effective approach for its metabolic detoxification.
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Affiliation(s)
- Yu Fang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (Y.F.); (S.Z.); (J.W.); (Z.W.); (J.S.); (X.H.)
| | - Shuyan Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (Y.F.); (S.Z.); (J.W.); (Z.W.); (J.S.); (X.H.)
| | - Jianli Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (Y.F.); (S.Z.); (J.W.); (Z.W.); (J.S.); (X.H.)
| | - Lianghong Yin
- Zhejiang Provincial Key Laboratory of Resources Protection and Innovation of Traditional Chinese Medicine, Zhejiang A&F University, Hangzhou 311300, China;
| | - Hailing Zhang
- Department of Biological Engineering, College of Life Science, Yantai University, Yantai 264005, China;
| | - Zhen Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (Y.F.); (S.Z.); (J.W.); (Z.W.); (J.S.); (X.H.)
| | - Jie Song
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (Y.F.); (S.Z.); (J.W.); (Z.W.); (J.S.); (X.H.)
| | - Xiaoqing Hu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (Y.F.); (S.Z.); (J.W.); (Z.W.); (J.S.); (X.H.)
- Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Xiaoyuan Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; (Y.F.); (S.Z.); (J.W.); (Z.W.); (J.S.); (X.H.)
- Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China
- Correspondence: ; Tel./Fax: +86-510-85329239
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18
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Jung H, Han J, Oh M. Improved production of 2,3-butanediol and isobutanol by engineering electron transport chain in Escherichia coli. Microb Biotechnol 2021; 14:213-226. [PMID: 32954676 PMCID: PMC7888471 DOI: 10.1111/1751-7915.13669] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 09/02/2020] [Accepted: 09/03/2020] [Indexed: 12/17/2022] Open
Abstract
The electron transport chain (ETC) is one of the major energy generation pathways in microorganisms under aerobic condition. Higher yield of ATP can be achieved through oxidative phosphorylation with consumption of NADH than with substrate level phosphorylation. However, most value-added metabolites are in an electrochemically reduced state, which requires reducing equivalent NADH as a cofactor. Therefore, optimal production of value-added metabolites should be balanced with ETC in terms of energy production. In this study, we attempted to reduce the activity of ETC to secure availability of NADH. The ETC mutants exhibited poor growth rate and production of fermentative metabolites compared to parental strain. Introduction of heterologous pathways for synthesis of 2,3-butanediol and isobutanol to ETC mutants resulted in increased titres and yields of the metabolites. ETC mutants yielded higher NADH/NAD+ ratio but similar ATP content than that by the parental strain. Furthermore, ETC mutants operated fermentative metabolism pathways independent of oxygen supply in large-scale fermenter, resulting in increased yield and titre of 2,3-butanediol. Thus, engineering of ETC is a useful metabolic engineering approach for production of reduced metabolites.
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Affiliation(s)
- Hwi‐Min Jung
- Department of Chemical and Biological EngineeringKorea University145 Anam‐ro, Seongbuk‐guSeoul02841Korea
| | - Jae‐Ho Han
- Department of Chemical and Biological EngineeringKorea University145 Anam‐ro, Seongbuk‐guSeoul02841Korea
| | - Min‐Kyu Oh
- Department of Chemical and Biological EngineeringKorea University145 Anam‐ro, Seongbuk‐guSeoul02841Korea
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19
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Lee IPA, Andam CP. Pan-genome diversification and recombination in Cronobacter sakazakii, an opportunistic pathogen in neonates, and insights to its xerotolerant lifestyle. BMC Microbiol 2019; 19:306. [PMID: 31881843 PMCID: PMC6935241 DOI: 10.1186/s12866-019-1664-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Accepted: 11/26/2019] [Indexed: 01/14/2023] Open
Abstract
Background Cronobacter sakazakii is an emerging opportunistic bacterial pathogen known to cause neonatal and pediatric infections, including meningitis, necrotizing enterocolitis, and bacteremia. Multiple disease outbreaks of C. sakazakii have been documented in the past few decades, yet little is known of its genomic diversity, adaptation, and evolution. Here, we analyzed the pan-genome characteristics and phylogenetic relationships of 237 genomes of C. sakazakii and 48 genomes of related Cronobacter species isolated from diverse sources. Results The C. sakazakii pan-genome contains 17,158 orthologous gene clusters, and approximately 19.5% of these constitute the core genome. Phylogenetic analyses reveal the presence of at least ten deep branching monophyletic lineages indicative of ancestral diversification. We detected enrichment of functions involved in proton transport and rotational mechanism in accessory genes exclusively found in human-derived strains. In environment-exclusive accessory genes, we detected enrichment for those involved in tryptophan biosynthesis and indole metabolism. However, we did not find significantly enriched gene functions for those genes exclusively found in food strains. The most frequently detected virulence genes are those that encode proteins associated with chemotaxis, enterobactin synthesis, ferrienterobactin transporter, type VI secretion system, galactose metabolism, and mannose metabolism. The genes fos which encodes resistance against fosfomycin, a broad-spectrum cell wall synthesis inhibitor, and mdf(A) which encodes a multidrug efflux transporter were found in nearly all genomes. We found that a total of 2991 genes in the pan-genome have had a history of recombination. Many of the most frequently recombined genes are associated with nutrient acquisition, metabolism and toxin production. Conclusions Overall, our results indicate that the presence of a large accessory gene pool, ability to switch between ecological niches, a diverse suite of antibiotic resistance, virulence and niche-specific genes, and frequent recombination partly explain the remarkable adaptability of C. sakazakii within and outside the human host. These findings provide critical insights that can help define the development of effective disease surveillance and control strategies for Cronobacter-related diseases.
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Affiliation(s)
- Isaiah Paolo A Lee
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH, 03824, USA
| | - Cheryl P Andam
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH, 03824, USA.
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20
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Wang YD, Liao JY, Chiang CJ, Chao YP. A simple strategy to effectively produce d-lactate in crude glycerol-utilizing Escherichia coli. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:273. [PMID: 31832096 PMCID: PMC6864932 DOI: 10.1186/s13068-019-1615-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 11/13/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Fed-batch fermentation has been conventionally implemented for the production of lactic acid with a high titer and high productivity. However, its operation needs a complicated control which increases the production cost. RESULTS This issue was addressed by simplifying the production scheme. Escherichia coli was manipulated for its glycerol dissimilation and d-lactate synthesis pathways and then subjected to adaptive evolution under high crude glycerol. Batch fermentation in the two-stage mode was performed by controlling the dissolved oxygen (DO), and the evolved strain deprived of poxB enabled production of 100 g/L d-lactate with productivity of 1.85 g/L/h. To increase productivity, the producer strain was further evolved to improve its growth rate on crude glycerol. The fermentation was performed to undergo the aerobic growth with low substrate, followed by the anaerobic production with high substrate. Moreover, the intracellular redox of the strain was balanced by fulfillment of the anaerobic respiratory chain with nitrate reduction. Without controlling the DO, the microbial fermentation resulted in the homofermentative production of d-lactate (ca. 0.97 g/g) with a titer of 115 g/L and productivity of 3.29 g/L/h. CONCLUSIONS The proposed fermentation strategy achieves the highest yield based on crude glycerol and a comparable titer and productivity as compared to the approach by fed-batch fermentation. It holds a promise to sustain the continued development of the crude glycerol-based biorefinery.
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Affiliation(s)
- Yao-De Wang
- Department of Chemical Engineering, Feng Chia University, 100 Wenhwa Road, Taichung, 40724 Taiwan
| | - Jin-Yi Liao
- Department of Chemical Engineering, Feng Chia University, 100 Wenhwa Road, Taichung, 40724 Taiwan
| | - Chung-Jen Chiang
- Department of Medical Laboratory Science and Biotechnology, China Medical University, No. 91, Hsueh-Shih Road, Taichung, 40402 Taiwan
| | - Yun-Peng Chao
- Department of Chemical Engineering, Feng Chia University, 100 Wenhwa Road, Taichung, 40724 Taiwan
- Department of Medical Research, China Medical University Hospital, Taichung, 40447 Taiwan
- Department of Health and Nutrition Biotechnology, Asia University, Taichung, 41354 Taiwan
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21
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Han Q, Eiteman MA. Acetate formation during recombinant protein production in Escherichia coli K-12 with an elevated NAD(H) pool. Eng Life Sci 2019; 19:770-780. [PMID: 32624970 DOI: 10.1002/elsc.201900045] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 08/15/2019] [Accepted: 08/21/2019] [Indexed: 12/14/2022] Open
Abstract
Acetate formation is a disadvantage in the use of Escherichia coli for recombinant protein production, and many studies have focused on optimizing fermentation processes or altering metabolism to eliminate acetate accumulation. In this study, E. coli MEC697 (MG1655 nadR nudC mazG) maintained a larger pool of NAD(H) compared to the wild-type control, and also accumulated lower concentrations of acetate when grown in batch culture on glucose. In steady-state cultures, the elevated total NAD(H) found in MEC697 delayed the threshold dilution rate for acetate formation to a growth rate of 0.27 h-1. Batch and fed-batch processes using MEC697 were examined for the production of β-galactosidase as a model recombinant protein. Fed-batch culture of MEC697/pTrc99A-lacZ compared to MG1655/pTrc99A-lacZ at a growth rate of 0.22 h-1 showed only a modest increase of protein formation. However, 1 L batch growth of MEC697/pTrc99A-lacZ resulted in 50% lower acetate formation compared to MG1655/pTrc99A-lacZ and a two-fold increase in recombinant protein production.
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Affiliation(s)
- Qi Han
- School of Chemical Materials and Biomedical Engineering University of Georgia Athens GA USA
| | - Mark A Eiteman
- School of Chemical Materials and Biomedical Engineering University of Georgia Athens GA USA
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22
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Wang C, Wang Z, You Y, Xu W, Lv Z, Liu Z, Chen W, Shi Y. Response of Arthrobacter QD 15-4 to dimethyl phthalate by regulating energy metabolism and ABC transporters. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 174:146-152. [PMID: 30825737 DOI: 10.1016/j.ecoenv.2019.02.078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 02/22/2019] [Accepted: 02/25/2019] [Indexed: 06/09/2023]
Abstract
Ubiquitous dimethyl phthalate (DMP) has severely threatened environmental safety and the health of organisms. Therefore, it is necessary to degrade DMP, removing it from the environment. Microbiological degradation is an efficient and safe method for degrading DMP. In this study, the response of Arthrobacter QD 15-4 to DMP was investigated. The results showed that the growth of Arthrobacter QD 15-4 was not impacted by DMP and Arthrobacter QD 15-4 could degrade DMP. RNA-Seq and RT-qPCR results showed that DMP treatment caused some changes in the expression of key genes in Arthrobacter QD 15-4. The transcriptional expressions of pstSCAB and phoU were downregulated by DMP. The transcriptional expressions of potACD, gluBC, oppAB, pdhAB, aceAF, gltA were upregulated by DMP. The genes are mainly involved in regulating energy metabolism and ATP-binding cassette (ABC) transporters. The increasing of pyruvic acid and citrate in Arthrobacter QD 15-4 further supported the energy metabolism was improved by DMP. It was clearly shown that Arthrobacter QD 15-4 made response to dimethyl phthalate by regulating energy metabolism and ABC transporters.
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Affiliation(s)
- Chunlong Wang
- School of Life Science and Agriculture and Forestry, Qiqihar University, Qiqihar, Heilongjiang 161006, China
| | - Zhigang Wang
- School of Life Science and Agriculture and Forestry, Qiqihar University, Qiqihar, Heilongjiang 161006, China.
| | - Yimin You
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Weihui Xu
- School of Life Science and Agriculture and Forestry, Qiqihar University, Qiqihar, Heilongjiang 161006, China
| | - Zhihang Lv
- School of Life Science and Agriculture and Forestry, Qiqihar University, Qiqihar, Heilongjiang 161006, China
| | - Zeping Liu
- School of Life Science and Agriculture and Forestry, Qiqihar University, Qiqihar, Heilongjiang 161006, China
| | - Wenjing Chen
- School of Life Science and Agriculture and Forestry, Qiqihar University, Qiqihar, Heilongjiang 161006, China
| | - Yiran Shi
- School of Life Science and Agriculture and Forestry, Qiqihar University, Qiqihar, Heilongjiang 161006, China
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Trichez D, Auriol C, Baylac A, Irague R, Dressaire C, Carnicer-Heras M, Heux S, François JM, Walther T. Engineering of Escherichia coli for Krebs cycle-dependent production of malic acid. Microb Cell Fact 2018; 17:113. [PMID: 30012131 PMCID: PMC6048880 DOI: 10.1186/s12934-018-0959-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/06/2018] [Indexed: 11/27/2022] Open
Abstract
Background Malate is a C4-dicarboxylic acid widely used as an acidulant in the food and beverage industry. Rational engineering has been performed in the past for the development of microbial strains capable of efficient production of this metabolite. However, as malate can be a precursor for specialty chemicals, such as 2,4-dihydroxybutyric acid, that require additional cofactors NADP(H) and ATP, we set out to reengineer Escherichia coli for Krebs cycle-dependent production of malic acid that can satisfy these requirements. Results We found that significant malate production required at least simultaneous deletion of all malic enzymes and dehydrogenases, and concomitant expression of a malate-insensitive PEP carboxylase. Metabolic flux analysis using 13C-labeled glucose indicated that malate-producing strains had a very high flux over the glyoxylate shunt with almost no flux passing through the isocitrate dehydrogenase reaction. The highest malate yield of 0.82 mol/mol was obtained with E. coli Δmdh Δmqo ΔmaeAB ΔiclR ΔarcA which expressed malate-insensitive PEP carboxylase PpcK620S and NADH-insensitive citrate synthase GltAR164L. We also showed that inactivation of the dicarboxylic acid transporter DcuA strongly reduced malate production arguing for a pivotal role of this permease in malate export. Conclusions Since more NAD(P)H and ATP cofactors are generated in the Krebs cycle-dependent malate production when compared to pathways which depend on the function of anaplerotic PEP carboxylase or PEP carboxykinase enzymes, the engineered strain developed in this study can serve as a platform to increase biosynthesis of malate-derived metabolites such as 2,4-dihydroxybutyric acid. Electronic supplementary material The online version of this article (10.1186/s12934-018-0959-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Debora Trichez
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
| | - Clément Auriol
- TWB, 3 rue Ariane, 31520, Ramonville-St. Agnes, France.,Cinabio, Cinabio-Adisseo France S.A.S., 31077, Toulouse, France
| | - Audrey Baylac
- TWB, 3 rue Ariane, 31520, Ramonville-St. Agnes, France
| | - Romain Irague
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
| | | | | | - Stéphanie Heux
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
| | - Jean Marie François
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France. .,TWB, 3 rue Ariane, 31520, Ramonville-St. Agnes, France.
| | - Thomas Walther
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France.,TWB, 3 rue Ariane, 31520, Ramonville-St. Agnes, France.,Institute of Natural Materials Technology, Technische Universität Dresden, 01062, Dresden, Germany
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24
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Wang Q, Zhang Z, Zhu Y, He L, Sheng X. Impact of poxB, pta, and ackA genes on mineral-weathering of Enterobacter cloacae S71. J Basic Microbiol 2018; 58:633-642. [PMID: 29732559 DOI: 10.1002/jobm.201800013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 03/17/2018] [Accepted: 04/12/2018] [Indexed: 11/11/2022]
Abstract
In this study, biotite weathering behaviors were compared between mineral-weathering bacteria Enterobacter cloacae S71, mutant strains created by the deletion of poxB, pta, and ackA genes involved in acetate formation, and their complemented strains. Compared to strain S71, a decrease in bacterial growth was observed during the early and middle stages for the mutant ΔpoxB and at the middle and later stages for the mutants Δpta and ΔackA. Dissolved Al and Fe concentrations were lower during the early stage for strain ΔpoxB, at the early or middle stage for strain Δpta, and at the middle and later stages and throughout the weathering process for strain ΔackA, compared to strain S71. Acetate production was depressed during the early stage for strain ΔpoxB, at the early and middle stages for strain Δpta, and throughout the weathering process for strain ΔackA. Overall, the ackA gene exhibited a larger impact on dissolved Fe and acetate concentrations than both the poxB and pta genes. Reduced bacterial growth and lower dissolved Al, Fe, and acetate concentrations recovered by the complemented strains. These results show that strain S71 promoted mineral weathering through the production of acetic acid with distinctive impacts by the genes involved in acetate.
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Affiliation(s)
- Qi Wang
- College of Life Sciences, Nanjing Agricultural University, Nanjing, PR China
| | - Zhendong Zhang
- College of Life Sciences, Nanjing Agricultural University, Nanjing, PR China
| | - Ying Zhu
- College of Life Sciences, Nanjing Agricultural University, Nanjing, PR China
| | - Linyan He
- College of Life Sciences, Nanjing Agricultural University, Nanjing, PR China
| | - Xiafang Sheng
- College of Life Sciences, Nanjing Agricultural University, Nanjing, PR China
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25
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Current state and perspectives in hydrogen production by Escherichia coli: roles of hydrogenases in glucose or glycerol metabolism. Appl Microbiol Biotechnol 2018; 102:2041-2050. [DOI: 10.1007/s00253-018-8752-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 12/28/2017] [Accepted: 12/29/2017] [Indexed: 01/07/2023]
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26
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Kumar V, Park S. Potential and limitations of Klebsiella pneumoniae as a microbial cell factory utilizing glycerol as the carbon source. Biotechnol Adv 2018; 36:150-167. [DOI: 10.1016/j.biotechadv.2017.10.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 10/15/2017] [Accepted: 10/16/2017] [Indexed: 12/16/2022]
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27
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Abstract
Recent studies have revealed an important role for the Staphylococcus aureus CidC enzyme in cell death during the stationary phase and in biofilm development and have contributed to our understanding of the metabolic processes that are important in the induction of bacterial programmed cell death (PCD). To gain more insight into the characteristics of this enzyme, we performed an in-depth biochemical and biophysical analysis of its catalytic properties. In vitro experiments show that this flavoprotein catalyzes the oxidative decarboxylation of pyruvate to acetate and carbon dioxide. CidC efficiently reduces menadione, but not CoenzymeQ0, suggesting a specific role in the S. aureus respiratory chain. CidC exists as a monomer under neutral-pH conditions but tends to aggregate and bind to artificial lipid membranes at acidic pH, resulting in enhanced enzymatic activity. Unlike its Escherichia coli counterpart, PoxB, CidC does not appear to be activated by other amphiphiles like Triton X-100 or octyl β-d-glucopyranoside. In addition, only reduced CidC is protected from proteolytic cleavage by chymotrypsin, and unlike its homologues in other bacteria, protease treatment does not increase CidC enzymatic activity. Finally, CidC exhibits maximal activity at pH 5.5-5.8 and negligible activity at pH 7-8. The results of this study are consistent with a model in which CidC functions as a pyruvate:menaquinone oxidoreductase whose activity is induced at the cellular membrane during cytoplasmic acidification, a process previously shown to be important for the induction of bacterial PCD.
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Affiliation(s)
- Xinyan Zhang
- Department of Pharmaceutical Sciences and ‡Department of Pathology & Microbiology, University of Nebraska Medical Center , Omaha, Nebraska 68198-5900, United States
| | - Kenneth W Bayles
- Department of Pharmaceutical Sciences and ‡Department of Pathology & Microbiology, University of Nebraska Medical Center , Omaha, Nebraska 68198-5900, United States
| | - Sorin Luca
- Department of Pharmaceutical Sciences and ‡Department of Pathology & Microbiology, University of Nebraska Medical Center , Omaha, Nebraska 68198-5900, United States
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28
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Synthesis of citramalic acid from glycerol by metabolically engineered Escherichia coli. J Ind Microbiol Biotechnol 2017; 44:1483-1490. [PMID: 28744578 DOI: 10.1007/s10295-017-1971-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 07/18/2017] [Indexed: 10/19/2022]
Abstract
Citramalic acid (citramalate) serves as a five-carbon precursor for the chemical synthesis of methacrylic acid. We compared citramalate and acetate accumulation from glycerol using Escherichia coli strains expressing a modified citramalate synthase gene cimA from Methanococcus jannaschii. These studies revealed that gltA coding citrate synthase, leuC coding 3-isopropylmalate dehydratase, and acetate pathway genes play important roles in elevating citramalate and minimizing acetate formation. Controlled 1.0 L batch experiments confirmed that deletions in all three acetate-production genes (poxB, ackA, and pta) were necessary to reduce acetate formation to less than 1 g/L during citramalate production from 30 g/L glycerol. Fed-batch processes using MEC568/pZE12-cimA (gltA leuC ackA-pta poxB) generated over 31 g/L citramalate and less than 2 g/L acetate from either purified or crude glycerol at yields exceeding 0.50 g citramalate/g glycerol in 132 h. These results hold promise for the viable formation of citramalate from unrefined glycerol.
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29
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Parimi NS, Durie IA, Wu X, Niyas AMM, Eiteman MA. Eliminating acetate formation improves citramalate production by metabolically engineered Escherichia coli. Microb Cell Fact 2017. [PMID: 28637476 PMCID: PMC5480221 DOI: 10.1186/s12934-017-0729-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Citramalate, a chemical precursor to the industrially important methacrylic acid (MAA), can be synthesized using Escherichia coli overexpressing citramalate synthase (cimA gene). Deletion of gltA encoding citrate synthase and leuC encoding 3-isopropylmalate dehydratase were critical to achieving high citramalate yields. Acetate is an undesirable by-product potentially formed from pyruvate and acetyl-CoA, the precursors of citramalate during aerobic growth of E. coli. This study investigated strategies to minimize acetate and maximize citramalate production in E. coli mutants expressing the cimA gene. RESULTS Key knockouts that minimized acetate formation included acetate kinase (ackA), phosphotransacetylase (pta), and in particular pyruvate oxidase (poxB). Deletion of glucose 6-phosphate dehydrogenase (zwf) and ATP synthase (atpFH) aimed at improving glycolytic flux negatively impacted cell growth and citramalate accumulation in shake flasks. In a repetitive fed-batch process, E. coli gltA leuC ackA-pta poxB overexpressing cimA generated 54.1 g/L citramalate with a yield of 0.64 g/g glucose (78% of theoretical maximum yield), and only 1.4 g/L acetate in 87 h. CONCLUSIONS This study identified the gene deletions critical to reducing acetate accumulation during aerobic growth and citramalate production in metabolically engineered E. coli strains. The citramalate yield and final titer relative to acetate at the end of the fed-batch process are the highest reported to date (a mass ratio of citramalate to acetate of nearly 40) without being detrimental to citramalate productivity, significantly improving a potential process for the production of this five-carbon chemical.
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Affiliation(s)
- Naga Sirisha Parimi
- School of Chemical, Materials and Biomedical Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, 30602, USA
| | - Ian A Durie
- School of Chemical, Materials and Biomedical Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, 30602, USA
| | - Xianghao Wu
- School of Chemical, Materials and Biomedical Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, 30602, USA
| | - Afaq M M Niyas
- School of Chemical, Materials and Biomedical Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, 30602, USA
| | - Mark A Eiteman
- School of Chemical, Materials and Biomedical Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, 30602, USA.
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30
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Zhang JG, Zhang F, Thakur K, Hu F, Wei ZJ. Valorization of Spent Escherichia coli Media Using Green Microalgae Chlamydomonas reinhardtii and Feedstock Production. Front Microbiol 2017. [PMID: 28638375 PMCID: PMC5461289 DOI: 10.3389/fmicb.2017.01026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The coupling of Chlamydomonas reinhardtii biomass production for nutrients removal of Escherichia coli anaerobic broth (EAB) is thought to be an economically feasible option for the cultivation of microalgae. The feasibility of growing microalgae in using EAB high in nutrients for the production of more biomass was examined. EAB comprised of nutrient-abundant effluents, which can be used to produce microalgae biomass and remove environment pollutant simultaneously. In this study, C. reinhardtii 21gr (cc1690) was cultivated in different diluted E. coli anaerobic broth supplemented with trace elements under mixotrophic and heterotrophic conditions. The results showed that C. reinhardtii grown in 1×, 1/2×, 1/5× and 1/10×E. coli anaerobic broth under mixotrophic conditions exhibited specific growth rates of 2.71, 2.68, 1.45, and 1.13 day-1, and biomass production of 201.9, 184.2, 175.5, and 163.8 mg L-1, respectively. Under heterotrophic conditions, the specific growth rates were 1.80, 1.86, 1.75, and 1.02 day-1, and biomass production were 45.6, 29.4, 15.8, and 12.1 mg L-1, respectively. The removal efficiency of chemical oxygen demand, total-nitrogen and total-phosphorus from 1×E. coli anaerobic broth was 21.51, 22.41, and 15.53%. Moreover, the dry biomass had relatively high carbohydrate (44.3%) and lipid content (18.7%). Therefore, this study provides an environmentally sustainable as well economical method for biomass production in promising model microalgae and subsequently paves the way for industrial use.
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Affiliation(s)
- Jian-Guo Zhang
- School of Food Science and Engineering, Hefei University of TechnologyHefei, China
| | - Fang Zhang
- School of Food Science and Engineering, Hefei University of TechnologyHefei, China
| | - Kiran Thakur
- School of Food Science and Engineering, Hefei University of TechnologyHefei, China
| | - Fei Hu
- School of Food Science and Engineering, Hefei University of TechnologyHefei, China
| | - Zhao-Jun Wei
- School of Food Science and Engineering, Hefei University of TechnologyHefei, China
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31
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Mechanistic insights into manganese oxidation of a soil-borne Mn(II)-oxidizing Escherichia coli strain by global proteomic and genetic analyses. Sci Rep 2017; 7:1352. [PMID: 28465578 PMCID: PMC5430989 DOI: 10.1038/s41598-017-01552-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 03/30/2017] [Indexed: 11/20/2022] Open
Abstract
An iTRAQ-based comparative and quantitative proteomics analysis of a soil-borne Mn(II)-oxidizing bacterium, Escherichia coli MB266, was conducted during the exponential and stationary growth phases. A total of 1850 proteins were identified in 4 samples, of which 373 and 456 proteins were significantly up- or down-regulated in at least one pairwise comparison, respectively. The iTRAQ data indicated that several enzymes involved in fatty acid metabolism (i.e., FabA, FabD and FabZ) and pyruvate metabolism (particularly pyruvate oxidase PoxB) were significantly up-regulated, while those related to the tricarboxylic acid cycle (such as FrdB, FumB and AcnA) and methylcitrate cycle (i.e., PrpC) were inactivated in the presence of 1 mM Mn(II); the amounts of some stress response and signal transduction system-related proteins (i.e., Spy) were remarkably increased, and the cold shock protein CspD was significantly up-regulated during the exponential growth phase. However, all verified heat shock proteins remained unchanged. The reactive oxygen species response and some redox enzymes might also be involved in Mn oxidation processes. The involvement of several cellular proteins in Mn(II) oxidation, including PoxB, Spy and MCO266, was further confirmed by gene disruption and expression complementation experiments. Based on these results, a signal transduction mechanism coupled to Mn oxidation was proposed.
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32
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Enjalbert B, Millard P, Dinclaux M, Portais JC, Létisse F. Acetate fluxes in Escherichia coli are determined by the thermodynamic control of the Pta-AckA pathway. Sci Rep 2017; 7:42135. [PMID: 28186174 PMCID: PMC5301487 DOI: 10.1038/srep42135] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 12/28/2016] [Indexed: 12/30/2022] Open
Abstract
Escherichia coli excretes acetate upon growth on fermentable sugars, but the regulation of this production remains elusive. Acetate excretion on excess glucose is thought to be an irreversible process. However, dynamic 13C-metabolic flux analysis revealed a strong bidirectional exchange of acetate between E. coli and its environment. The Pta-AckA pathway was found to be central for both flux directions, while alternative routes (Acs or PoxB) play virtually no role in glucose consumption. Kinetic modelling of the Pta-AckA pathway predicted that its flux is thermodynamically controlled by the extracellular acetate concentration in vivo. Experimental validations confirmed that acetate production can be reduced and even reversed depending solely on its extracellular concentration. Consistently, the Pta-AckA pathway can rapidly switch from acetate production to consumption. Contrary to current knowledge, E. coli is thus able to co-consume glucose and acetate under glucose excess. These metabolic capabilities were confirmed on other glycolytic substrates which support the growth of E. coli in the gut. These findings highlight the dual role of the Pta-AckA pathway in acetate production and consumption during growth on glycolytic substrates, uncover a novel regulatory mechanism that controls its flux in vivo, and significantly expand the metabolic capabilities of E. coli.
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Affiliation(s)
- Brice Enjalbert
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
| | - Pierre Millard
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
| | - Mickael Dinclaux
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
| | | | - Fabien Létisse
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
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33
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Ewald J, Bartl M, Dandekar T, Kaleta C. Optimality principles reveal a complex interplay of intermediate toxicity and kinetic efficiency in the regulation of prokaryotic metabolism. PLoS Comput Biol 2017; 13:e1005371. [PMID: 28212377 PMCID: PMC5315294 DOI: 10.1371/journal.pcbi.1005371] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 01/19/2017] [Indexed: 11/18/2022] Open
Abstract
A precise and rapid adjustment of fluxes through metabolic pathways is crucial for organisms to prevail in changing environmental conditions. Based on this reasoning, many guiding principles that govern the evolution of metabolic networks and their regulation have been uncovered. To this end, methods from dynamic optimization are ideally suited since they allow to uncover optimality principles behind the regulation of metabolic networks. We used dynamic optimization to investigate the influence of toxic intermediates in connection with the efficiency of enzymes on the regulation of a linear metabolic pathway. Our results predict that transcriptional regulation favors the control of highly efficient enzymes with less toxic upstream intermediates to reduce accumulation of toxic downstream intermediates. We show that the derived optimality principles hold by the analysis of the interplay between intermediate toxicity and pathway regulation in the metabolic pathways of over 5000 sequenced prokaryotes. Moreover, using the lipopolysaccharide biosynthesis in Escherichia coli as an example, we show how knowledge about the relation of regulation, kinetic efficiency and intermediate toxicity can be used to identify drug targets, which control endogenous toxic metabolites and prevent microbial growth. Beyond prokaryotes, we discuss the potential of our findings for the development of antifungal drugs.
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Affiliation(s)
- Jan Ewald
- Research Group Theoretical Systems Biology, Department of Bioinformatics, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Martin Bartl
- Research Group Theoretical Systems Biology, Department of Bioinformatics, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Thomas Dandekar
- Department of Bioinformatics, Biocenter, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Christoph Kaleta
- Research Group Medical Systems Biology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
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34
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Rubino F, Carberry C, M Waters S, Kenny D, McCabe MS, Creevey CJ. Divergent functional isoforms drive niche specialisation for nutrient acquisition and use in rumen microbiome. ISME JOURNAL 2017; 11:932-944. [PMID: 28085156 PMCID: PMC5364355 DOI: 10.1038/ismej.2016.172] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Revised: 07/28/2016] [Accepted: 09/21/2016] [Indexed: 01/16/2023]
Abstract
Many microbes in complex competitive environments share genes for acquiring and utilising nutrients, questioning whether niche specialisation exists and if so, how it is maintained. We investigated the genomic signatures of niche specialisation in the rumen microbiome, a highly competitive, anaerobic environment, with limited nutrient availability determined by the biomass consumed by the host. We generated individual metagenomic libraries from 14 cows fed an ad libitum diet of grass silage and calculated functional isoform diversity for each microbial gene identified. The animal replicates were used to calculate confidence intervals to test for differences in diversity of functional isoforms between microbes that may drive niche specialisation. We identified 153 genes with significant differences in functional isoform diversity between the two most abundant bacterial genera in the rumen (Prevotella and Clostridium). We found Prevotella possesses a more diverse range of isoforms capable of degrading hemicellulose, whereas Clostridium for cellulose. Furthermore, significant differences were observed in key metabolic processes indicating that isoform diversity plays an important role in maintaining their niche specialisation. The methods presented represent a novel approach for untangling complex interactions between microorganisms in natural environments and have resulted in an expanded catalogue of gene targets central to rumen cellulosic biomass degradation.
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Affiliation(s)
- Francesco Rubino
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, UK.,Animal and Bioscience Research Department, Teagasc, Grange, Dunsany, Co., Meath, Ireland
| | - Ciara Carberry
- Animal and Bioscience Research Department, Teagasc, Grange, Dunsany, Co., Meath, Ireland.,School of Agriculture, University College Dublin, Dublin, Ireland
| | - Sinéad M Waters
- Animal and Bioscience Research Department, Teagasc, Grange, Dunsany, Co., Meath, Ireland
| | - David Kenny
- Animal and Bioscience Research Department, Teagasc, Grange, Dunsany, Co., Meath, Ireland
| | - Matthew S McCabe
- Animal and Bioscience Research Department, Teagasc, Grange, Dunsany, Co., Meath, Ireland
| | - Christopher J Creevey
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, UK
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35
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Akita H, Nakashima N, Hoshino T. Pyruvate production using engineered Escherichia coli. AMB Express 2016; 6:94. [PMID: 27718215 PMCID: PMC5055523 DOI: 10.1186/s13568-016-0259-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/28/2016] [Indexed: 12/24/2022] Open
Abstract
Pyruvate plays an essential role in the central carbon metabolism of multiple organisms and is used as a raw material in the chemical, biochemical and pharmaceutical industries. To meet demand, large amounts of pyruvate are produced through fermentation processes. Here we describe a simple and efficient method for producing pyruvate in Escherichia coli. To stop carbon flux from pyruvate to fatty acids, the accBC genes, which encode the enzyme that catalyzes the first step of fatty acid biosynthesis and is essential for vegetative growth, were manipulated within the genome; its native promoter was replaced with the tetracycline (or doxycycline)-regulated promoter and the corresponding transcriptional regulator genes. The resulting strain grew normally in the presence of doxycycline, but showed poor growth upon withdrawal of doxycycline. Using this strain, we developed a high pyruvate producing strain (strain LAFCPCPt-accBC-aceE), in which the tetracycline-regulated promoter was also introduced upstream of aceE, and the ackA-pta, adhE, cra, ldhA, pflB and poxB genes were deleted. After determining the optimal culture conditions for this strain, the final pyruvate concentration reached 26.1 g L-1 after 72 h with a theoretical yield of 55.6 %. These levels are high enough to indicate that the developed strain has the potential for application to industrial production of pyruvate.
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36
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Wu X, Eiteman MA. Production of citramalate by metabolically engineeredEscherichia coli. Biotechnol Bioeng 2016; 113:2670-2675. [DOI: 10.1002/bit.26035] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 05/19/2016] [Accepted: 06/13/2016] [Indexed: 11/12/2022]
Affiliation(s)
- Xianghao Wu
- BioChemical Engineering; College of Engineering; University of Georgia; Athens Georgia 30602
| | - Mark A. Eiteman
- BioChemical Engineering; College of Engineering; University of Georgia; Athens Georgia 30602
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37
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Bernal V, Castaño-Cerezo S, Cánovas M. Acetate metabolism regulation in Escherichia coli: carbon overflow, pathogenicity, and beyond. Appl Microbiol Biotechnol 2016; 100:8985-9001. [DOI: 10.1007/s00253-016-7832-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 08/22/2016] [Accepted: 08/24/2016] [Indexed: 12/11/2022]
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38
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Tao L, Xie M, Chiew GGY, Wang Z, Chen WN, Wang X. Improving electron trans-inner membrane movements in microbial electrocatalysts. Chem Commun (Camb) 2016; 52:6292-5. [PMID: 27086742 DOI: 10.1039/c6cc00976j] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel nondestructive strategy of improving electron trans-inner membrane movements in bioelectrocatalysts is realized by overexpressing NADH dehydrogenase II in the inner membrane. A microbial fuel cell loaded with these improved bioelectrocatalysts shows significantly enhanced performance based on promoting the utilization of intracellular primary electron donors in bioelectrocatalysts.
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Affiliation(s)
- Le Tao
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Avenue, 637459, Singapore.
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39
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Metabolic engineering of Klebsiella pneumoniae and in silico investigation for enhanced 2,3-butanediol production. Biotechnol Lett 2016; 38:975-82. [DOI: 10.1007/s10529-016-2062-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 02/02/2016] [Indexed: 11/26/2022]
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40
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Lin J, Zhang Y, Xu D, Xiang G, Jia Z, Fu S, Gong H. Deletion of poxB, pta, and ackA improves 1,3-propanediol production by Klebsiella pneumoniae. Appl Microbiol Biotechnol 2015; 100:2775-84. [DOI: 10.1007/s00253-015-7237-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 11/29/2015] [Accepted: 12/07/2015] [Indexed: 12/24/2022]
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Kawai M, Higashiura N, Hayasaki K, Okamoto N, Takami A, Hirakawa H, Matsushita K, Azuma Y. Complete genome and gene expression analyses of Asaia bogorensis reveal unique responses to culture with mammalian cells as a potential opportunistic human pathogen. DNA Res 2015; 22:357-66. [PMID: 26358298 PMCID: PMC4596401 DOI: 10.1093/dnares/dsv018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 08/13/2015] [Indexed: 11/14/2022] Open
Abstract
Asaia bogorensis, a member of acetic acid bacteria (AAB), is an aerobic bacterium isolated from flowers and fruits, as well as an opportunistic pathogen that causes human peritonitis and bacteraemia. Here, we determined the complete genomic sequence of the As. bogorensis type strain NBRC 16594, and conducted comparative analyses of gene expression under different conditions of co-culture with mammalian cells and standard AAB culture. The genome of As. bogorensis contained 2,758 protein-coding genes within a circular chromosome of 3,198,265 bp. There were two complete operons encoding cytochrome bo3-type ubiquinol terminal oxidases: cyoABCD-1 and cyoABCD-2. The cyoABCD-1 operon was phylogenetically common to AAB genomes, whereas the cyoABCD-2 operon belonged to a lineage distinctive from the cyoABCD-1 operon. Interestingly, cyoABCD-1 was less expressed under co-culture conditions than under the AAB culture conditions, whereas the converse was true for cyoABCD-2. Asaia bogorensis shared pathogenesis-related genes with another pathogenic AAB, Granulibacter bethesdensis, including a gene coding pathogen-specific large bacterial adhesin and additional genes for the inhibition of oxidation and antibiotic resistance. Expression alteration of the respiratory chain and unique hypothetical genes may be key traits that enable the bacterium to survive under the co-culture conditions.
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Affiliation(s)
- Mikihiko Kawai
- Faculty of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Wakayama, Japan Advanced Low Carbon Technology Research and Development Program (ALCA), Japan Science and Technology Agency (JST), Tokyo, Japan
| | - Norie Higashiura
- Faculty of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Wakayama, Japan Advanced Low Carbon Technology Research and Development Program (ALCA), Japan Science and Technology Agency (JST), Tokyo, Japan
| | - Kimie Hayasaki
- Faculty of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Wakayama, Japan
| | - Naruhei Okamoto
- Faculty of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Wakayama, Japan
| | - Akiko Takami
- Faculty of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Wakayama, Japan Advanced Low Carbon Technology Research and Development Program (ALCA), Japan Science and Technology Agency (JST), Tokyo, Japan
| | | | - Kazunobu Matsushita
- Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi, Yamaguchi, Japan
| | - Yoshinao Azuma
- Faculty of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Wakayama, Japan
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13C metabolic flux analysis at a genome-scale. Metab Eng 2015; 32:12-22. [PMID: 26358840 DOI: 10.1016/j.ymben.2015.08.006] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 08/10/2015] [Accepted: 08/20/2015] [Indexed: 11/21/2022]
Abstract
Metabolic models used in 13C metabolic flux analysis generally include a limited number of reactions primarily from central metabolism. They typically omit degradation pathways, complete cofactor balances, and atom transition contributions for reactions outside central metabolism. This study addresses the impact on prediction fidelity of scaling-up mapping models to a genome-scale. The core mapping model employed in this study accounts for (75 reactions and 65 metabolites) primarily from central metabolism. The genome-scale metabolic mapping model (GSMM) (697 reaction and 595 metabolites) is constructed using as a basis the iAF1260 model upon eliminating reactions guaranteed not to carry flux based on growth and fermentation data for a minimal glucose growth medium. Labeling data for 17 amino acid fragments obtained from cells fed with glucose labeled at the second carbon was used to obtain fluxes and ranges. Metabolic fluxes and confidence intervals are estimated, for both core and genome-scale mapping models, by minimizing the sum of square of differences between predicted and experimentally measured labeling patterns using the EMU decomposition algorithm. Overall, we find that both topology and estimated values of the metabolic fluxes remain largely consistent between core and GSM model. Stepping up to a genome-scale mapping model leads to wider flux inference ranges for 20 key reactions present in the core model. The glycolysis flux range doubles due to the possibility of active gluconeogenesis, the TCA flux range expanded by 80% due to the availability of a bypass through arginine consistent with labeling data, and the transhydrogenase reaction flux was essentially unresolved due to the presence of as many as five routes for the inter-conversion of NADPH to NADH afforded by the genome-scale model. By globally accounting for ATP demands in the GSMM model the unused ATP decreased drastically with the lower bound matching the maintenance ATP requirement. A non-zero flux for the arginine degradation pathway was identified to meet biomass precursor demands as detailed in the iAF1260 model. Inferred ranges for 81% of the reactions in the genome-scale metabolic (GSM) model varied less than one-tenth of the basis glucose uptake rate (95% confidence test). This is because as many as 411 reactions in the GSM are growth coupled meaning that the single measurement of biomass formation rate locks the reaction flux values. This implies that accurate biomass formation rate and composition are critical for resolving metabolic fluxes away from central metabolism and suggests the importance of biomass composition (re)assessment under different genetic and environmental backgrounds. In addition, the loss of information associated with mapping fluxes from MFA on a core model to a GSM model is quantified.
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Jantama K, Polyiam P, Khunnonkwao P, Chan S, Sangproo M, Khor K, Jantama SS, Kanchanatawee S. Efficient reduction of the formation of by-products and improvement of production yield of 2,3-butanediol by a combined deletion of alcohol dehydrogenase, acetate kinase-phosphotransacetylase, and lactate dehydrogenase genes in metabolically engineered Klebsiella oxytoca in mineral salts medium. Metab Eng 2015; 30:16-26. [PMID: 25895450 DOI: 10.1016/j.ymben.2015.04.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 03/18/2015] [Accepted: 04/08/2015] [Indexed: 11/24/2022]
Abstract
Klebsiella oxytoca KMS005 (∆adhE∆ackA-pta∆ldhA) was metabolically engineered to improve 2,3-butanediol (BDO) yield. Elimination of alcohol dehydrogenase E (adhE), acetate kinase A-phosphotransacetylase (ackA-pta), and lactate dehydrogenase A (ldhA) enzymes allowed BDO production as a primary pathway for NADH re-oxidation, and significantly reduced by-products. KMS005 was screened for the efficient glucose utilization by metabolic evolution. KMS005-73T improved BDO production at a concentration of 23.5±0.5 g/L with yield of 0.46±0.02 g/g in mineral salts medium containing 50 g/L glucose in a shake flask. KMS005-73T also exhibited BDO yields of about 0.40-0.42 g/g from sugarcane molasses, cassava starch, and maltodextrin. During fed-batch fermentation, KMS005-73T produced BDO at a concentration, yield, and overall and specific productivities of 117.4±4.5 g/L, 0.49±0.02 g/g, 1.20±0.05 g/Lh, and 27.2±1.1 g/gCDW, respectively. No acetoin, lactate, and formate were detected, and only trace amounts of acetate and ethanol were formed. The strain also produced the least by-products and the highest BDO yield among other Klebsiella strains previously developed.
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Affiliation(s)
- Kaemwich Jantama
- Metabolic Engineering Research Unit, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Suranaree Sub-District, Muang District, 30000 Nakhon Ratchasima, Thailand.
| | - Pattharasedthi Polyiam
- Metabolic Engineering Research Unit, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Suranaree Sub-District, Muang District, 30000 Nakhon Ratchasima, Thailand
| | - Panwana Khunnonkwao
- Metabolic Engineering Research Unit, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Suranaree Sub-District, Muang District, 30000 Nakhon Ratchasima, Thailand
| | - Sitha Chan
- Metabolic Engineering Research Unit, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Suranaree Sub-District, Muang District, 30000 Nakhon Ratchasima, Thailand
| | - Maytawadee Sangproo
- Metabolic Engineering Research Unit, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Suranaree Sub-District, Muang District, 30000 Nakhon Ratchasima, Thailand
| | - Kirin Khor
- Metabolic Engineering Research Unit, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Suranaree Sub-District, Muang District, 30000 Nakhon Ratchasima, Thailand
| | - Sirima Suvarnakuta Jantama
- Division of Biopharmacy, Faculty of Pharmaceutical Sciences, Ubon Ratchathani University, Warinchamrap, Ubon Ratchathani 34190, Thailand
| | - Sunthorn Kanchanatawee
- Metabolic Engineering Research Unit, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Suranaree Sub-District, Muang District, 30000 Nakhon Ratchasima, Thailand
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Klatte S, Wendisch VF. Role of L-alanine for redox self-sufficient amination of alcohols. Microb Cell Fact 2015; 14:9. [PMID: 25612558 PMCID: PMC4336473 DOI: 10.1186/s12934-014-0189-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 12/30/2014] [Indexed: 11/25/2022] Open
Abstract
Background In white biotechnology biocatalysis represents a key technology for chemical functionalization of non-natural compounds. The plasmid-born overproduction of an alcohol dehydrogenase, an L-alanine-dependent transaminase and an alanine dehydrogenase allows for redox self-sufficient amination of alcohols in whole cell biotransformation. Here, conditions to optimize the whole cell biocatalyst presented in (Bioorg Med Chem 22:5578–5585, 2014), and the role of L-alanine for efficient amine functionalization of 1,10-decanediol to 1,10-diaminodecane were analyzed. Results The enzymes of the cascade for amine functionalization of alcohols were characterized in vitro to find optimal conditions for an efficient process. Transaminase from Chromobacterium violaceum, TaCv, showed three-fold higher catalytic efficiency than transaminase from Vibrio fluvialis, TaVf, and improved production at 37°C. At 42°C, TaCv was more active, which matched thermostable alcohol dehydrogenase and alanine dehydrogenase and improved the 1,10-diaminodecane production rate four-fold. To study the role of L-alanine in the whole cell biotransformation, the L-alanine concentration was varied and 1,10.diaminodecane formation tested with constant 10 mM 1,10- decanediol and 100 mM NH4Cl. Only 5.6% diamine product were observed without added L-alanine. L-alanine concentrations equimolar to that of the alcohol enabled for 94% product formation but higher L-alanine concentrations allowed for 100% product formation. L-alanine was consumed by the E. coli biocatalyst, presumably due to pyruvate catabolism since up to 16 mM acetate accumulated. Biotransformation employing E. coli strain YYC202/pTrc99a-ald-adh-taCv, which is unable to catabolize pyruvate, resulted in conversion with a selectivity of 42 mol-%. Biotransformation with E. coli strains only lacking pyruvate oxidase PoxB showed similar reduced amination of 1,10-decanediol indicating that oxidative decarboxylation of pyruvate to acetate by PoxB is primarily responsible for pyruvate catabolism during redox self-sufficient amination of alcohols using this whole cell biocatalyst. Conclusion The replacement of the transaminase TaVf by TaCv, which showed higher activity at 42°C, in the artificial operon ald-adh-ta improved amination of alcohols in whole cell biotransformation. The addition of L-alanine, which was consumed by E. coli via pyruvate catabolism, was required for 100% product formation possibly by providing maintenance energy. Metabolic engineering revealed that pyruvate catabolism occurred primarily via oxidative decarboxylation to acetate by PoxB under the chosen biotranformation conditions. Electronic supplementary material The online version of this article (doi:10.1186/s12934-014-0189-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Stephanie Klatte
- Chair of Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, Universitaetsstr. 25, 33615, Bielefeld, Germany.
| | - Volker F Wendisch
- Chair of Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, Universitaetsstr. 25, 33615, Bielefeld, Germany.
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Zhang Y, Lin Z, Liu Q, Li Y, Wang Z, Ma H, Chen T, Zhao X. Engineering of Serine-Deamination pathway, Entner-Doudoroff pathway and pyruvate dehydrogenase complex to improve poly(3-hydroxybutyrate) production in Escherichia coli. Microb Cell Fact 2014; 13:172. [PMID: 25510247 PMCID: PMC4279783 DOI: 10.1186/s12934-014-0172-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 11/23/2014] [Indexed: 12/16/2022] Open
Abstract
Background Poly(3-hydroxybutyrate) (PHB), a biodegradable bio-plastic, is one of the most common homopolymer of polyhydroxyalkanoates (PHAs). PHB is synthesized by a variety of microorganisms as intracellular carbon and energy storage compounds in response to environmental stresses. Bio-based production of PHB from renewable feedstock is a promising and sustainable alternative to the petroleum-based chemical synthesis of plastics. In this study, a novel strategy was applied to improve the PHB biosynthesis from different carbon sources. Results In this research, we have constructed E. coli strains to produce PHB by engineering the Serine-Deamination (SD) pathway, the Entner-Doudoroff (ED) pathway, and the pyruvate dehydrogenase (PDH) complex. Firstly, co-overexpression of sdaA (encodes L-serine deaminase), L-serine biosynthesis genes and pgk (encodes phosphoglycerate kinase) activated the SD Pathway, and the resulting strain SD02 (pBHR68), harboring the PHB biosynthesis genes from Ralstonia eutropha, produced 4.86 g/L PHB using glucose as the sole carbon source, representing a 2.34-fold increase compared to the reference strain. In addition, activating the ED pathway together with overexpressing the PDH complex further increased the PHB production to 5.54 g/L with content of 81.1% CDW. The intracellular acetyl-CoA concentration and the [NADPH]/[NADP+] ratio were enhanced after the modification of SD pathway, ED pathway and the PDH complex. Meanwhile, these engineering strains also had a significant increase in PHB concentration and content when xylose or glycerol was used as carbon source. Conclusions Significant levels of PHB biosynthesis from different kinds of carbon sources can be achieved by engineering the Serine-Deamination pathway, Entner-Doudoroff pathway and pyruvate dehydrogenase complex in E. coli JM109 harboring the PHB biosynthesis genes from Ralstonia eutropha. This work demonstrates a novel strategy for improving PHB production in E. coli. The strategy reported here should be useful for the bio-based production of PHB from renewable resources.
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Affiliation(s)
- Yan Zhang
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, People's Republic of China. .,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China. .,Edinburg-Tianjin Joint Research Centre for Systems Biology and Synthetic Biology, Tianjin University, Tianjin, 300072, People's Republic of China. .,Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
| | - Zhenquan Lin
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, People's Republic of China. .,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China. .,Edinburg-Tianjin Joint Research Centre for Systems Biology and Synthetic Biology, Tianjin University, Tianjin, 300072, People's Republic of China. .,Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
| | - Qiaojie Liu
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, People's Republic of China. .,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China. .,Edinburg-Tianjin Joint Research Centre for Systems Biology and Synthetic Biology, Tianjin University, Tianjin, 300072, People's Republic of China. .,Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
| | - Yifan Li
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, People's Republic of China. .,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China. .,Edinburg-Tianjin Joint Research Centre for Systems Biology and Synthetic Biology, Tianjin University, Tianjin, 300072, People's Republic of China. .,Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
| | - Zhiwen Wang
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, People's Republic of China. .,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China. .,Edinburg-Tianjin Joint Research Centre for Systems Biology and Synthetic Biology, Tianjin University, Tianjin, 300072, People's Republic of China. .,Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
| | - Hongwu Ma
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, People's Republic of China.
| | - Tao Chen
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, People's Republic of China. .,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China. .,Edinburg-Tianjin Joint Research Centre for Systems Biology and Synthetic Biology, Tianjin University, Tianjin, 300072, People's Republic of China. .,Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
| | - Xueming Zhao
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072, People's Republic of China. .,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China. .,Edinburg-Tianjin Joint Research Centre for Systems Biology and Synthetic Biology, Tianjin University, Tianjin, 300072, People's Republic of China. .,Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
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Chen XZ, Xia Y, Shen W, Fan Y, Govender A, Wang ZX. Engineering glycolysis branch pathways of Escherichia coli to improve heterologous protein expression. Process Biochem 2014. [DOI: 10.1016/j.procbio.2014.09.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Yang W, Catalanotti C, D'Adamo S, Wittkopp TM, Ingram-Smith CJ, Mackinder L, Miller TE, Heuberger AL, Peers G, Smith KS, Jonikas MC, Grossman AR, Posewitz MC. Alternative acetate production pathways in Chlamydomonas reinhardtii during dark anoxia and the dominant role of chloroplasts in fermentative acetate production. THE PLANT CELL 2014; 26:4499-518. [PMID: 25381350 PMCID: PMC4277214 DOI: 10.1105/tpc.114.129965] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 07/15/2014] [Accepted: 10/15/2014] [Indexed: 05/18/2023]
Abstract
Chlamydomonas reinhardtii insertion mutants disrupted for genes encoding acetate kinases (EC 2.7.2.1) (ACK1 and ACK2) and a phosphate acetyltransferase (EC 2.3.1.8) (PAT2, but not PAT1) were isolated to characterize fermentative acetate production. ACK1 and PAT2 were localized to chloroplasts, while ACK2 and PAT1 were shown to be in mitochondria. Characterization of the mutants showed that PAT2 and ACK1 activity in chloroplasts plays a dominant role (relative to ACK2 and PAT1 in mitochondria) in producing acetate under dark, anoxic conditions and, surprisingly, also suggested that Chlamydomonas has other pathways that generate acetate in the absence of ACK activity. We identified a number of proteins associated with alternative pathways for acetate production that are encoded on the Chlamydomonas genome. Furthermore, we observed that only modest alterations in the accumulation of fermentative products occurred in the ack1, ack2, and ack1 ack2 mutants, which contrasts with the substantial metabolite alterations described in strains devoid of other key fermentation enzymes.
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Affiliation(s)
- Wenqiang Yang
- Carnegie Institution for Science, Department of Plant Biology, Stanford, California 94305
| | - Claudia Catalanotti
- Carnegie Institution for Science, Department of Plant Biology, Stanford, California 94305
| | - Sarah D'Adamo
- Colorado School of Mines, Department of Chemistry and Geochemistry, Golden, Colorado 80401
| | - Tyler M Wittkopp
- Carnegie Institution for Science, Department of Plant Biology, Stanford, California 94305 Stanford University, Department of Biology, Stanford, California 94305
| | - Cheryl J Ingram-Smith
- Clemson University, Department of Genetics and Biochemistry, Clemson, South Carolina 29634
| | - Luke Mackinder
- Carnegie Institution for Science, Department of Plant Biology, Stanford, California 94305
| | - Tarryn E Miller
- Colorado School of Mines, Department of Chemistry and Geochemistry, Golden, Colorado 80401
| | - Adam L Heuberger
- Colorado State University, Proteomics and Metabolomics Facility, Fort Collins, Colorado 80523
| | - Graham Peers
- Colorado State University, Department of Biology, Fort Collins, Colorado 80523
| | - Kerry S Smith
- Clemson University, Department of Genetics and Biochemistry, Clemson, South Carolina 29634
| | - Martin C Jonikas
- Carnegie Institution for Science, Department of Plant Biology, Stanford, California 94305
| | - Arthur R Grossman
- Carnegie Institution for Science, Department of Plant Biology, Stanford, California 94305
| | - Matthew C Posewitz
- Colorado School of Mines, Department of Chemistry and Geochemistry, Golden, Colorado 80401
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Hermes FA, Cronan JE. An NAD synthetic reaction bypasses the lipoate requirement for aerobic growth of Escherichia coli strains blocked in succinate catabolism. Mol Microbiol 2014; 94:10.1111/mmi.12822. [PMID: 25303731 PMCID: PMC4393350 DOI: 10.1111/mmi.12822] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/07/2014] [Indexed: 11/30/2022]
Abstract
The lipoate coenzyme is essential for function of the pyruvate (PDH) and 2-oxoglutarate (OGDH) dehydrogenases and thus for aerobic growth of Escherichia coli. LipB catalyzes the first step in lipoate synthesis, transfer of an octanoyl moiety from the fatty acid synthetic intermediate, octanoyl-ACP, to PDH and OGDH. E. coli also encodes LplA, a ligase that in presence of exogenous octanoate (or lipoate) can bypass loss of LipB. LplA imparts ΔlipB strains with a 'leaky' growth phenotype on aerobic glucose minimal medium supplemented with succinate (which bypasses the OGDH-catalyzed reaction), because it scavenges an endogenous octanoate pool to activate PDH. Here we characterize a ΔlipB suppressor strain that did not require succinate supplementation, but did require succinyl-CoA ligase, confirming the presence of alternative source(s) of cytosolic succinate. We report that suppression requires inactivation of succinate dehydrogenase (SDH), which greatly reduces the cellular requirement for succinate. In the suppressor strain succinate is produced by three enzymes, any one of which will suffice in the absence of SDH. These three enzymes are: trace levels of OGDH, the isocitrate lyase of the glyoxylate shunt and an unanticipated source, aspartate oxidase, the enzyme catalyzing the first step of nicotinamide biosynthesis.
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Affiliation(s)
- Fatemah A. Hermes
- Department of Microbiology, University of Illinois at Urbana-Champaign
| | - John E. Cronan
- Department of Microbiology, University of Illinois at Urbana-Champaign
- Department of Biochemistry, University of Illinois at Urbana-Champaign
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Vuoristo KS, Mars AE, Sangra JV, Springer J, Eggink G, Sanders JPM, Weusthuis RA. Metabolic engineering of itaconate production in Escherichia coli. Appl Microbiol Biotechnol 2014; 99:221-8. [PMID: 25277412 DOI: 10.1007/s00253-014-6092-x] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Revised: 09/08/2014] [Accepted: 09/10/2014] [Indexed: 11/24/2022]
Abstract
Interest in sustainable development has led to efforts to replace petrochemical-based monomers with biomass-based ones. Itaconic acid, a C5-dicarboxylic acid, is a potential monomer for the chemical industry with many prospective applications. cis-aconitate decarboxylase (CadA) is the key enzyme of itaconate production, converting the citric acid cycle intermediate cis-aconitate into itaconate. Heterologous expression of cadA from Aspergillus terreus in Escherichia coli resulted in low CadA activities and production of trace amounts of itaconate on Luria-Bertani (LB) medium (<10 mg/L). CadA was primarily present as inclusion bodies, explaining the low activity. The activity was significantly improved by using lower cultivation temperatures and mineral medium, and this resulted in enhanced itaconate titres (240 mg/L). The itaconate titre was further increased by introducing citrate synthase and aconitase from Corynebacterium glutamicum and by deleting the genes encoding phosphate acetyltransferase and lactate dehydrogenase. These deletions in E. coli's central metabolism resulted in the accumulation of pyruvate, which is a precursor for itaconate biosynthesis. As a result, itaconate production in aerobic bioreactor cultures was increased up to 690 mg/L. The maximum yield obtained was 0.09 mol itaconate/mol glucose. Strategies for a further improvement of itaconate production are discussed.
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Affiliation(s)
- Kiira S Vuoristo
- Bioprocess Engineering, Wageningen University, Wageningen, The Netherlands,
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50
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Goris T, Schubert T, Gadkari J, Wubet T, Tarkka M, Buscot F, Adrian L, Diekert G. Insights into organohalide respiration and the versatile catabolism ofSulfurospirillum multivoransgained from comparative genomics and physiological studies. Environ Microbiol 2014; 16:3562-80. [DOI: 10.1111/1462-2920.12589] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 07/31/2014] [Indexed: 12/13/2022]
Affiliation(s)
- Tobias Goris
- Department of Applied and Ecological Microbiology; Institute of Microbiology; Friedrich Schiller University; Jena 07743 Germany
| | - Torsten Schubert
- Department of Applied and Ecological Microbiology; Institute of Microbiology; Friedrich Schiller University; Jena 07743 Germany
| | - Jennifer Gadkari
- Department of Applied and Ecological Microbiology; Institute of Microbiology; Friedrich Schiller University; Jena 07743 Germany
| | - Tesfaye Wubet
- Department of Soil Ecology; Helmholtz Centre for Environmental Research - UFZ; Halle 06120 Germany
| | - Mika Tarkka
- Department of Soil Ecology; Helmholtz Centre for Environmental Research - UFZ; Halle 06120 Germany
| | - Francois Buscot
- Department of Soil Ecology; Helmholtz Centre for Environmental Research - UFZ; Halle 06120 Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle - Jena - Leipzig; Leipzig 04103 Germany
| | - Lorenz Adrian
- Department Isotope Biogeochemistry; Helmholtz Centre for Environmental Research - UFZ; Leipzig 04318 Germany
| | - Gabriele Diekert
- Department of Applied and Ecological Microbiology; Institute of Microbiology; Friedrich Schiller University; Jena 07743 Germany
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