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Ganguly S. The pivotal role of Corynebacterium glutamicum in l-Glutamic acid fermentation: A concise review. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2022. [DOI: 10.1016/j.bcab.2022.102578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Xu YY, Hua KJ, Huang Z, Zhou PP, Wen JB, Jin C, Bao J. Cellulosic hydrocarbons production by engineering dual synthesis pathways in Corynebacterium glutamicum. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:29. [PMID: 35292099 PMCID: PMC8922798 DOI: 10.1186/s13068-022-02129-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 03/07/2022] [Indexed: 12/30/2022]
Abstract
Background Lignocellulose provides the only practical carbohydrates feedstock for sustainable bioproduction of hydrocarbons as future alternative of fossil fuels. Production of hydrocarbons from lignocellulose is achieved by a biorefinery process chain including pretreatment to breakdown the crystalline structure for cellulase-catalyzed hydrolysis, detoxification of inhibitory compounds generated during pretreatment, enzymatic hydrolysis to fermentable monosaccharide sugars, and fermentation to hydrocarbon products. The major barriers on fermentative production of hydrocarbons from lignocellulose include two aspects: one is the inherent stress of pretreatment-derived inhibitors on microbial cells, the other is the toxicity of hydrocarbons to cell membranes. The microbial cell factory should be tolerant to both inhibitor stress and hydrocarbons toxicity. Results Corynebacterium glutamicum was selected as the starting strain of hydrocarbons synthesis since it is well adapted to lignocellulose hydrolysate environment. The dual hydrocarbon synthesis pathways were constructed in an industrial C. glutamicum S9114 strain. The first pathway was the regular one in microalgae composed of fatty acyl-acyl carrier protein (fatty acyl-ACP) reductase (AAR) and aldehyde deformylating oxygenase (ADO) with fatty acyl-ACP as precursor. The second pathway was the direct decarboxylation of free fatty acid by fatty acid decarboxylase (OleT) using the rich fatty acids from the disruption of the transcriptional regulator fasR gene. The transmembrane transportation of hydrocarbon products was avoided by secretively expressing the fatty acid decarboxylase (OleT) to the extracellular space. The hydrocarbons generation from glucose reached 29.2 mg/L, in which the direct decarboxylation pathway contributed more than 70% of the total hydrocarbons generation, and the AAR–ADO pathway contributed the rest 30%. Conclusion The dual hydrocarbon synthesis pathways (OleT and AAR–ADO pathways) were constructed in the inhibitors tolerant C. glutamicum S9114 strain for hydrocarbon production using lignocellulose feedstock as the starting feedstock. When corn stover was used for hydrocarbons production after dry acid pretreatment and biodetoxification, the hydrocarbons generation reached 16.0 mg/L. This study provided a new strategy for hydrocarbons synthesis using microbial cell factory suitable for lignocellulose feedstock. Supplementary Information The online version contains supplementary material available at 10.1186/s13068-022-02129-7.
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Affiliation(s)
- Ying-Ying Xu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Ke-Jun Hua
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Zhen Huang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Ping-Ping Zhou
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.,College of Food and Biology Engineering, Henan University of Animal Husbandry and Economy, 6 Longzihu North Road, Zhengzhou, 450046, Henan, China
| | - Jing-Bai Wen
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.,School of Chemical and Biological Engineering, Yichun University, 576 Xuefu Road, Yichun, 336000, Jiangxi, China
| | - Ci Jin
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Jie Bao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.
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Jin C, Li J, Huang Z, Han X, Bao J. Engineering Corynebacterium glutamicum for synthesis of poly(3-hydroxybutyrate) from lignocellulose biomass. Biotechnol Bioeng 2022; 119:1598-1613. [PMID: 35180315 DOI: 10.1002/bit.28065] [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: 11/24/2021] [Revised: 01/28/2022] [Accepted: 02/12/2022] [Indexed: 11/07/2022]
Abstract
Lignocellulose is the only feasible carbohydrates feedstock for commercial scale and carbon neutral production of poly(3-hydroxybutyrate) (PHB) biopolymer by its great abundance and availability. Microbial cell factories for fermentative PHB synthesis are highly restricted by the growth suppression of inhibitors from lignocellulose pretreatment. This study targeted on a potential PHB-producing cell factory Corynebacterium glutamicum owing to its strong inhibitors tolerance. A systematic metabolic engineering was conducted starting with the stable PHB synthesis pathway construction from glucose and xylose, followed by the enhancement of PHB synthesis on PHA synthase activity and stability, cell morphology modification, and growth factors regulation. The relocation of the PHA synthase on the cell membrane guided by secrete signal peptides and cell membrane display motifs increased the PHB content by 2.4 folds. Excessive nitrogen preferentially promoted the PHB synthesis capacity and resulted in the PHB content increased by 13.3 folds. Modification of the genes responsible for cell division changed the cell morphology but the cell size was not enlarged to a PHB accumulation favorable environment. The metabolic engineering of C. glutamicum resulted in a high fermentative production of PHB using wheat straw as feedstock. This study provided an important microbial cell factory choice for PHB production using lignocellulose feedstock. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Ci Jin
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Jing Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Zhen Huang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Xushen Han
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Jie Bao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
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Nie Z, Liu P, Wang Y, Guo X, Tan Z, Shen J, Tang Z, Lin J, Sun J, Zheng P, Zhu L. Directed Evolution and Rational Design of Mechanosensitive Channel MscCG2 for Improved Glutamate Excretion Efficiency. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:15660-15669. [PMID: 34928605 DOI: 10.1021/acs.jafc.1c07086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Mechanosensitive amino acid exporters have drawn increasing attention due to their important roles in extracellular accumulation of the target amino acids. Protein engineering is a powerful approach to tailor the properties of amino acid exporters and illustrate structure-function relationships. Here we report the first protein engineering effort on the mechanosensitive glutamate exporter MscCG2 from Corynebacterium glutamicum for improved excretion efficiency of glutamate and understanding of the structure-function relationship. MscCG2 was engineered through directed evolution and computer-assisted design with a coupled assay in microtiter plate format. Improved MscCG2 variants were identified with up to 2.5-fold increase in the level of glutamate excretion in the early stage of fermentation and 1.5-fold in the late stage of fermentation under experimental conditions. Furthermore, the identified variants exhibited enhanced efflux of 4-fluoroglutamate (4-FG), an analog of glutamate. Structure analysis employing homology modeling and molecular dynamics (MD) simulation reveal that identified amino acid substitutions enlarge the size of the seven portals on the equator of MscCG2 and expand the narrowest rim of its inner channel, respectively. This study demonstrates the great potential of protein engineering in improving the secretion efficiency of exporters for enhanced bioproduction.
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Affiliation(s)
- Zhihua Nie
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Pi Liu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Yu Wang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Xuan Guo
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Zijian Tan
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Jie Shen
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Zijing Tang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Jianping Lin
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Jibin Sun
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Ping Zheng
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Leilei Zhu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
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Wen J, Bao J. Improved fermentative γ-aminobutyric acid production by secretory expression of glutamate decarboxylase by Corynebacterium glutamicum. J Biotechnol 2021; 331:19-25. [PMID: 33711360 DOI: 10.1016/j.jbiotec.2021.03.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/24/2021] [Accepted: 03/01/2021] [Indexed: 02/01/2023]
Abstract
Fermentative production of γ-aminobutyric acid by the glutamate overproducing Corynebacterium glutamicum from cheap sugar feedstock is generally regarded as one of the most promising methods to reduce the production cost. However, the intracellularly expressed glutamate decarboxylase in C. glutamicum often showed feeble catalysis activity to convert glutamate into γ-aminobutyric acid. Here we tried to secretory express glutamate decarboxylase to achieve efficient extracellular decarboxylation of glutamate, thus improving the γ-aminobutyric acid production by C. glutamicum. We first tested glutamate decarboxylases from different sources, and the mutated glutamate decarboxylase GadBmut from E. coli with better catalytic performance was selected. Then, a signal peptide of the SEC translocation pathway directed the successful secretion of glutamate decarboxylase in C. glutamicum. The extracellular catalysis by secreted glutamate decarboxylase increased the γ-aminobutyric acid generation by three-fold, compared with intracellular catalysis. Enhancing glutamate decarboxylase expression and decreasing γ-aminobutyric acid degradation further increased γ-aminobutyric acid production by 39 %. The fed-batch fermentation of the engineered C. glutamicum strain reached the record high titer (77.6 ± 0.0 g /L), overall yield (0.44 ± 0.00 g/g glucose), and productivity (1.21 ± 0.00 g/L/h). This study demonstrated a unique design of extracellular catalysis for efficient γ-aminobutyric acid production by C. glutamicum.
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Affiliation(s)
- Jingbai Wen
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China; School of Chemical and Biological Engineering, Yichun University, 576 Xuefu Road, Yichun, Jiangxi 336000, China
| | - Jie Bao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
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Zhang B, Jiang Y, Li Z, Wang F, Wu XY. Recent Progress on Chemical Production From Non-food Renewable Feedstocks Using Corynebacterium glutamicum. Front Bioeng Biotechnol 2021; 8:606047. [PMID: 33392171 PMCID: PMC7775722 DOI: 10.3389/fbioe.2020.606047] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 10/31/2020] [Indexed: 11/13/2022] Open
Abstract
Due to the non-renewable nature of fossil fuels, microbial fermentation is considered a sustainable approach for chemical production using glucose, xylose, menthol, and other complex carbon sources represented by lignocellulosic biomass. Among these, xylose, methanol, arabinose, glycerol, and other alternative feedstocks have been identified as superior non-food sustainable carbon substrates that can be effectively developed for microbe-based bioproduction. Corynebacterium glutamicum is a model gram-positive bacterium that has been extensively engineered to produce amino acids and other chemicals. Recently, in order to reduce production costs and avoid competition for human food, C. glutamicum has also been engineered to broaden its substrate spectrum. Strengthening endogenous metabolic pathways or assembling heterologous ones enables C. glutamicum to rapidly catabolize a multitude of carbon sources. This review summarizes recent progress in metabolic engineering of C. glutamicum toward a broad substrate spectrum and diverse chemical production. In particularly, utilization of lignocellulosic biomass-derived complex hybrid carbon source represents the futural direction for non-food renewable feedstocks was discussed.
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Affiliation(s)
- Bin Zhang
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, China.,Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, Jiangxi Agricultural University, Nanchang, China
| | - Yan Jiang
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, China.,Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, Jiangxi Agricultural University, Nanchang, China
| | - Zhimin Li
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, China.,Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, Jiangxi Agricultural University, Nanchang, China
| | - Fei Wang
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, China.,Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, Jiangxi Agricultural University, Nanchang, China
| | - Xiao-Yu Wu
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, China.,Jiangxi Engineering Laboratory for the Development and Utilization of Agricultural Microbial Resources, Jiangxi Agricultural University, Nanchang, China
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Han X, Li L, Bao J. Microbial extraction of biotin from lignocellulose biomass and its application on glutamic acid production. BIORESOURCE TECHNOLOGY 2019; 288:121523. [PMID: 31146079 DOI: 10.1016/j.biortech.2019.121523] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 05/17/2019] [Accepted: 05/18/2019] [Indexed: 06/09/2023]
Abstract
Biotin (vitamin B7) is an important nutrient for various fermentations. It is abundant in agricultural lignocellulose biomass and maintains stable in biorefinery processing chain including acid pretreatment, biodetoxification and saccharification. Here we show a microbial extraction of biotin from biotin-rich corn leaves hydrolysate. Corynebacterium glutamicum was found to have the highest biotin uptake capacity among different biotin auxotrophic microorganisms, and it was further significantly increased by overexpressing the bioYMN gene cluster encoding biotin transporter. Finally 250 folds greater biotin was extracted by recombinant C. glutamicum (303.8 mg/kg dry cell) from virgin corn leaves (1.2 mg/kg), which was far higher than that in commonly used fermentation additives including yeast extract (∼2 mg/kg), molasses (∼1 mg/kg) and corn steep liquor (∼0.75 mg/kg). The biotin extracted from corn leaves was successfully applied to glutamic acid fermentation. This is the first report on microbial extraction of biotin from lignocellulose biomass and fermentation promotion application.
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Affiliation(s)
- Xushen Han
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Li Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Jie Bao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
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Ahmed F, Yan Z, Bao J. Dry biodetoxification of acid pretreated wheat straw for cellulosic ethanol fermentation. BIORESOUR BIOPROCESS 2019. [DOI: 10.1186/s40643-019-0260-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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Han X, Li L, Wei C, Zhang J, Bao J. Facilitation of l-Lactic Acid Fermentation by Lignocellulose Biomass Rich in Vitamin B Compounds. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:7082-7086. [PMID: 31199642 DOI: 10.1021/acs.jafc.9b02297] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Vitamins are important nutrients for many fermentations, but they are generally costly. Agricultural lignocellulose biomass contains considerable amounts of vitamin B compounds, but these water-soluble vitamins are easily lost into wastewater discharge during pretreatment or detoxification of lignocellulose in biorefinery processes. Here, we showed that the dry acid pretreatment and biodetoxification process allowed the preservation of significant amounts of vitamin B, which promoted l-lactic acid fermentation efficiency significantly. Supplementation with specific vitamin B compounds, VB3 and VB5, into corn stover hydrolysate led to further increases of cellulosic l-lactic acid yield and fermentation rates. This study provided a new solution for the enhancement of biorefinery fermentation efficiency by using vitamin B compounds in lignocellulose biomass.
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Affiliation(s)
- Xushen Han
- State Key Laboratory of Bioreactor Engineering , East China University of Science and Technology , 130 Meilong Road , Shanghai 200237 , China
| | - Li Li
- State Key Laboratory of Bioreactor Engineering , East China University of Science and Technology , 130 Meilong Road , Shanghai 200237 , China
| | - Chengxiang Wei
- State Key Laboratory of Bioreactor Engineering , East China University of Science and Technology , 130 Meilong Road , Shanghai 200237 , China
| | - Jian Zhang
- State Key Laboratory of Bioreactor Engineering , East China University of Science and Technology , 130 Meilong Road , Shanghai 200237 , China
| | - Jie Bao
- State Key Laboratory of Bioreactor Engineering , East China University of Science and Technology , 130 Meilong Road , Shanghai 200237 , China
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Zhou P, Khushk I, Gao Q, Bao J. Tolerance and transcriptional analysis of Corynebacterium glutamicum on biotransformation of toxic furaldehyde and benzaldehyde inhibitory compounds. J Ind Microbiol Biotechnol 2019; 46:951-963. [PMID: 30972584 DOI: 10.1007/s10295-019-02171-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Accepted: 04/01/2019] [Indexed: 11/26/2022]
Abstract
Furaldehydes and benzaldehydes are among the most toxic inhibitors from lignocellulose pretreatment on microbial growth and metabolism. The bioconversion of aldehyde inhibitors into less toxic alcohols or acids (biotransformation) is the prerequisite condition for efficient biorefinery fermentations. This study found that Corynebacterium glutamicum S9114 demonstrated excellent tolerance and biotransformation capacity to five typical aldehyde inhibitors including two furaldehydes: 2-furaldehyde (furfural), 5-(hydroxymethyl)-2-furaldehyde, and three benzaldehydes: 4-hydroxybenzaldehyde, 4-hydroxy-3-methoxybenzaldehyde (vanillin), and 4-hydroxy-3,5-dimethoxybenzaldehyde (syringaldehyde). Transcription levels of 93 genes hypothesized to be responsible for five aldehydes biotransformation were examined by qRT-PCR. Multiple genes showed significantly up-regulated expression against furaldehydes or benzaldehydes. Overexpression of CGS9114_RS01115 in C. glutamicum resulted in the increased conversion of all five aldehyde inhibitors. The significant oxidoreductase genes responsible for each or multiple inhibitors biotransformation identified in this study will serve as a component of key gene device library for robust biorefinery fermentation strains development in the future biorefinery applications.
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Affiliation(s)
- Pingping Zhou
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Imrana Khushk
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Qiuqiang Gao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Jie Bao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China.
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Wen J, Bao J. Engineering Corynebacterium glutamicum triggers glutamic acid accumulation in biotin-rich corn stover hydrolysate. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:86. [PMID: 31011369 PMCID: PMC6463653 DOI: 10.1186/s13068-019-1428-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 04/08/2019] [Indexed: 05/22/2023]
Abstract
BACKGROUND Lignocellulose biomass contains high amount of biotin and resulted in an excessive biotin condition for cellulosic glutamic acid accumulation by Corynebacterium glutamicum. Penicillin or ethambutol triggers cellulosic glutamic acid accumulation, but they are not suitable for practical use due to the fermentation instability and environmental concerns. Efficient glutamic acid production from lignocellulose feedstocks should be achieved without any chemical inductions. RESULTS An industrial strain C. glutamicum S9114 was metabolically engineered to achieve efficient glutamic acid accumulation in biotin-excessive corn stover hydrolysate. Among the multiple metabolic engineering efforts, two pathway regulations effectively triggered the glutamic acid accumulation in lignocellulose hydrolysate. The C-terminal truncation of glutamate secretion channel MscCG (ΔC110) led to the successful glutamic acid secretion in corn stover hydrolysate without inductions. Then the α-oxoglutarate dehydrogenase complex (ODHC) activity was attenuated by regulating odhA RBS sequence, and glutamic acid accumulation was further elevated for more than fivefolds. The obtained C. glutamicum XW6 strain reached a record-high titer of 65.2 g/L with the overall yield of 0.63 g/g glucose using corn stover as the starting feedstock without any chemical induction. CONCLUSIONS Metabolic engineering method was successfully applied to achieve efficient glutamic acid in biotin-rich lignocellulose hydrolysate for the first time. This study demonstrated the high potential of glutamic acid production from lignocellulose feedstock.
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Affiliation(s)
- Jingbai Wen
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237 China
| | - Jie Bao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237 China
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Han X, Hong F, Liu G, Bao J. An Approach of Utilizing Water-Soluble Carbohydrates in Lignocellulose Feedstock for Promotion of Cellulosic l-Lactic Acid Production. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:10225-10232. [PMID: 30207160 DOI: 10.1021/acs.jafc.8b03592] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Agricultural lignocellulose biomass generally contains certain amounts of water-soluble carbohydrates (WSC) such as glucose, fructose, or sucrose. These sugars are generally degraded in pretreatment at high temperature or discharged with wastewater in a detoxification process. This study proposed an approach of utilizing frequently ignored water-soluble carbohydrates for promotion of cellulosic l-lactic acid production. A simple solid state fermentation was performed during a corn stover storage period to convert the sugars into l-lactic acid and then a dry biorefining technology was applied to convert cellulose and hemicellulose fractions into the same l-lactic acid product. The 5-hydroxymethylfurfural (HMF) formation in pretreatment was significantly reduced and the consequent biodetoxification time was shortened. l-Lactic acid production was increased from 130.2 g/L to 139.0 g/L, and the minimum l-lactic acid selling price was reduced by 5.9%. This study provided an important option of biorefinery processing technology for production of value added biochemicals.
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Affiliation(s)
- Xushen Han
- State Key Laboratory of Bioreactor Engineering , East China University of Science and Technology , 130 Meilong Road , Shanghai 200237 , China
| | - Feng Hong
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University , Shanghai 201620 , China
| | - Gang Liu
- State Key Laboratory of Bioreactor Engineering , East China University of Science and Technology , 130 Meilong Road , Shanghai 200237 , China
| | - Jie Bao
- State Key Laboratory of Bioreactor Engineering , East China University of Science and Technology , 130 Meilong Road , Shanghai 200237 , China
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