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Kim J, Cheong YE, Yu S, Jin YS, Kim KH. Strain engineering and metabolic flux analysis of a probiotic yeast Saccharomyces boulardii for metabolizing L-fucose, a mammalian mucin component. Microb Cell Fact 2022; 21:204. [PMID: 36207743 PMCID: PMC9541068 DOI: 10.1186/s12934-022-01926-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 09/19/2022] [Indexed: 11/24/2022] Open
Abstract
Background Saccharomyces boulardii is a probiotic yeast that exhibits antimicrobial and anti-toxin activities. Although S. boulardii has been clinically used for decades to treat gastrointestinal disorders, several studies have reported weak or no beneficial effects of S. boulardii administration in some cases. These conflicting results of S. boulardii efficacity may be due to nutrient deficiencies in the intestine that make it difficult for S. boulardii to maintain its metabolic activity. Results To enable S. boulardii to overcome any nutritional deficiencies in the intestine, we constructed a S. boulardii strain that could metabolize l-fucose, a major component of mucin in the gut epithelium. The fucU, fucI, fucK, and fucA from Escherichia coli and HXT4 from S. cerevisiae were overexpressed in S. boulardii. The engineered S. boulardii metabolized l-fucose and produced 1,2-propanediol under aerobic and anaerobic conditions. It also produced large amounts of 1,2-propanediol under strict anaerobic conditions. An in silico genome-scale metabolic model analysis was performed to simulate the growth of S. boulardii on l-fucose, and elementary flux modes were calculated to identify critical metabolic reactions for assimilating l-fucose. As a result, we found that the engineered S. boulardii consumes l-fucose via (S)-lactaldehyde-(S)-lactate-pyruvate pathway, which is highly oxygen dependent. Conclusion To the best of our knowledge, this is the first study in which S. cerevisiae and S. boulardii strains capable of metabolizing l-fucose have been constructed. This strategy could be used to enhance the metabolic activity of S. boulardii and other probiotic microorganisms in the gut. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-022-01926-x.
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Affiliation(s)
- Jungyeon Kim
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.,Department of Biotechnology, Graduate School, Korea University, Seoul, 02841, Republic of Korea
| | - Yu Eun Cheong
- Department of Biotechnology, Graduate School, Korea University, Seoul, 02841, Republic of Korea
| | - Sora Yu
- Department of Biotechnology, Graduate School, Korea University, Seoul, 02841, Republic of Korea
| | - Yong-Su Jin
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA. .,Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
| | - Kyoung Heon Kim
- Department of Biotechnology, Graduate School, Korea University, Seoul, 02841, Republic of Korea. .,Department of Food Bioscience and Technology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, Republic of Korea.
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Liu Y, Benitez MG, Chen J, Harrison E, Khusnutdinova AN, Mahadevan R. Opportunities and Challenges for Microbial Synthesis of Fatty Acid-Derived Chemicals (FACs). Front Bioeng Biotechnol 2021; 9:613322. [PMID: 33575251 PMCID: PMC7870715 DOI: 10.3389/fbioe.2021.613322] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 01/04/2021] [Indexed: 11/13/2022] Open
Abstract
Global warming and uneven distribution of fossil fuels worldwide concerns have spurred the development of alternative, renewable, sustainable, and environmentally friendly resources. From an engineering perspective, biosynthesis of fatty acid-derived chemicals (FACs) is an attractive and promising solution to produce chemicals from abundant renewable feedstocks and carbon dioxide in microbial chassis. However, several factors limit the viability of this process. This review first summarizes the types of FACs and their widely applications. Next, we take a deep look into the microbial platform to produce FACs, give an outlook for the platform development. Then we discuss the bottlenecks in metabolic pathways and supply possible solutions correspondingly. Finally, we highlight the most recent advances in the fast-growing model-based strain design for FACs biosynthesis.
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Affiliation(s)
- Yilan Liu
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
| | - Mauricio Garcia Benitez
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
| | - Jinjin Chen
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
| | - Emma Harrison
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
| | - Anna N. Khusnutdinova
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
| | - Radhakrishnan Mahadevan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
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Synthetic Methylotrophy in Yeasts: Towards a Circular Bioeconomy. Trends Biotechnol 2020; 39:348-358. [PMID: 33008643 DOI: 10.1016/j.tibtech.2020.08.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 08/07/2020] [Accepted: 08/24/2020] [Indexed: 01/04/2023]
Abstract
Mitigating climate change is a key driver for the development of sustainable and CO2-neutral production processes. In this regard, connecting carbon capture and utilization processes to derive microbial C1 fermentation substrates from CO2 is highly promising. This strategy uses methylotrophic microbes to unlock next-generation processes, converting CO2-derived methanol. Synthetic biology approaches in particular can empower synthetic methylotrophs to produce a variety of commodity chemicals. We believe that yeasts have outstanding potential for this purpose, because they are able to separate toxic intermediates and metabolic reactions in organelles. This compartmentalization can be harnessed to design superior synthetic methylotrophs, capable of utilizing methanol and other hitherto largely disregarded C1 compounds, thus supporting the establishment of a future circular economy.
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Imura M, Nitta K, Iwakiri R, Matsuda F, Shimizu H, Fukusaki E. Comparison of metabolic profiles of yeasts based on the difference of the Crabtree positive and negative. J Biosci Bioeng 2019; 129:52-58. [PMID: 31537452 DOI: 10.1016/j.jbiosc.2019.07.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 07/22/2019] [Accepted: 07/29/2019] [Indexed: 01/11/2023]
Abstract
The Crabtree effect involves energy management in which yeasts utilize glycolysis as the terminal electron acceptor instead of oxygen, despite the presence of sufficient dissolved oxygen, when oxygen concentrations exceed a certain limit. The Crabtree effect is detrimental to bakery yeast production, because it results in lower cellular glucose yields. Batch culture of Saccharomyces cerevisiae, a Crabtree positive yeast, decreased the cell yield of glucose and produced large amounts of ethanol despite a high specific glucose consumption rate compared to Candida utilis, a Crabtree negative yeast. This study investigated the effect of these characteristics on metabolite levels. We performed metabolome analysis of both yeasts during each growth phase of batch culture using liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry. Principle component analysis of metabolome data indicated that the Crabtree effect affected metabolites related to NADH synthesis in central metabolism. The amount of these metabolites in S. cerevisiae was lower than that in C. utilis. However, to maintain the specific glucose consumption rate at high levels, yeasts must avoid depletion of NAD+, which is essential for glucose utilization. Our results indicated that NADH was oxidized by converting acetaldehyde to ethanol in S. cerevisiae, which is in accordance with previous reports. Therefore, the specific NADH production rates of S. cerevisiae and C. utilis did not show a difference. This study suggested that NAD+/NADH ratio is disrupted by the Crabtree effect, which in turn influenced central metabolism and that S. cerevisiae maintained the NAD+/NADH ratio by producing ethanol.
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Affiliation(s)
- Makoto Imura
- Mitsubishi Corporation Life Sciences Limited, 1-6 Higashihama, Saiki, Oita 876-8580, Japan; Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Katsuaki Nitta
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Ryo Iwakiri
- Mitsubishi Corporation Life Sciences Limited, 1-6 Higashihama, Saiki, Oita 876-8580, Japan.
| | - Fumio Matsuda
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Hiroshi Shimizu
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Eiichiro Fukusaki
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
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De Mol ML, Snoeck N, De Maeseneire SL, Soetaert WK. Hidden antibiotics: Where to uncover? Biotechnol Adv 2018; 36:2201-2218. [DOI: 10.1016/j.biotechadv.2018.10.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 10/05/2018] [Accepted: 10/15/2018] [Indexed: 01/21/2023]
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Ishii J, Morita K, Ida K, Kato H, Kinoshita S, Hataya S, Shimizu H, Kondo A, Matsuda F. A pyruvate carbon flux tugging strategy for increasing 2,3-butanediol production and reducing ethanol subgeneration in the yeast Saccharomyces cerevisiae. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:180. [PMID: 29983743 PMCID: PMC6020211 DOI: 10.1186/s13068-018-1176-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 06/16/2018] [Indexed: 05/06/2023]
Abstract
BACKGROUND The yeast Saccharomyces cerevisiae is a promising host cell for producing a wide range of chemicals. However, attempts to metabolically engineer Crabtree-positive S. cerevisiae invariably face a common issue: how to reduce dominant ethanol production. Here, we propose a yeast metabolic engineering strategy for decreasing ethanol subgeneration involving tugging the carbon flux at an important hub branching point (e.g., pyruvate). Tugging flux at a central glycolytic overflow metabolism point arising from high glycolytic activity may substantially increase higher alcohol production in S. cerevisiae. We validated this possibility by testing 2,3-butanediol (2,3-BDO) production, which is routed via pyruvate as the important hub compound. RESULTS By searching for high-activity acetolactate synthase (ALS) enzymes that catalyze the important first-step reaction in 2,3-BDO biosynthesis, and tuning several fermentation conditions, we demonstrated that a stronger pyruvate pulling effect (tugging of pyruvate carbon flux) is very effective for increasing 2,3-BDO production and reducing ethanol subgeneration by S. cerevisiae. To further confirm the validity of the pyruvate carbon flux tugging strategy, we constructed an evolved pyruvate decarboxylase (PDC)-deficient yeast (PDCΔ) strain that lacked three isozymes of PDC. In parallel with re-sequencing to identify genomic mutations, liquid chromatography-tandem mass spectrometry analysis of intermediate metabolites revealed significant accumulation of pyruvate and NADH in the evolved PDCΔ strain. Harnessing the high-activity ALS and additional downstream enzymes in the evolved PDCΔ strain resulted in a high yield of 2,3-BDO (a maximum of 0.41 g g-1 glucose consumed) and no ethanol subgeneration, thereby confirming the utility of our strategy. Using this engineered strain, we demonstrated a high 2,3-BDO titer (81.0 g L-1) in a fed-batch fermentation using a high concentration of glucose as the sole carbon source. CONCLUSIONS We demonstrated that the pyruvate carbon flux tugging strategy is very effective for increasing 2,3-BDO production and decreasing ethanol subgeneration in Crabtree-positive S. cerevisiae. High activity of the common first-step enzyme for the conversion of pyruvate, which links to both the TCA cycle and amino acid biosynthesis, is likely important for the production of various chemicals by S. cerevisiae.
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Affiliation(s)
- Jun Ishii
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501 Japan
| | - Keisuke Morita
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Kengo Ida
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501 Japan
| | - Hiroko Kato
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501 Japan
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Shohei Kinoshita
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Shoko Hataya
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501 Japan
| | - Hiroshi Shimizu
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Akihiko Kondo
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501 Japan
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501 Japan
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro, Tsurumi, Yokohama, 230-0045 Japan
| | - Fumio Matsuda
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871 Japan
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro, Tsurumi, Yokohama, 230-0045 Japan
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Dzialo MC, Park R, Steensels J, Lievens B, Verstrepen KJ. Physiology, ecology and industrial applications of aroma formation in yeast. FEMS Microbiol Rev 2017; 41:S95-S128. [PMID: 28830094 PMCID: PMC5916228 DOI: 10.1093/femsre/fux031] [Citation(s) in RCA: 206] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 06/06/2017] [Indexed: 01/05/2023] Open
Abstract
Yeast cells are often employed in industrial fermentation processes for their ability to efficiently convert relatively high concentrations of sugars into ethanol and carbon dioxide. Additionally, fermenting yeast cells produce a wide range of other compounds, including various higher alcohols, carbonyl compounds, phenolic compounds, fatty acid derivatives and sulfur compounds. Interestingly, many of these secondary metabolites are volatile and have pungent aromas that are often vital for product quality. In this review, we summarize the different biochemical pathways underlying aroma production in yeast as well as the relevance of these compounds for industrial applications and the factors that influence their production during fermentation. Additionally, we discuss the different physiological and ecological roles of aroma-active metabolites, including recent findings that point at their role as signaling molecules and attractants for insect vectors.
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Affiliation(s)
- Maria C Dzialo
- Laboratory for Genetics and Genomics, Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Gaston Geenslaan 1, B-3001 Leuven, Belgium
- Laboratory for Systems Biology, VIB Center for Microbiology, Bio-Incubator, Gaston Geenslaan 1, 3001 Leuven, Belgium
| | - Rahel Park
- Laboratory for Genetics and Genomics, Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Gaston Geenslaan 1, B-3001 Leuven, Belgium
- Laboratory for Systems Biology, VIB Center for Microbiology, Bio-Incubator, Gaston Geenslaan 1, 3001 Leuven, Belgium
| | - Jan Steensels
- Laboratory for Genetics and Genomics, Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Gaston Geenslaan 1, B-3001 Leuven, Belgium
- Laboratory for Systems Biology, VIB Center for Microbiology, Bio-Incubator, Gaston Geenslaan 1, 3001 Leuven, Belgium
| | - Bart Lievens
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM), Department of Microbial and Molecular Systems, KU Leuven, Campus De Nayer, Fortsesteenweg 30A B-2860 Sint-Katelijne Waver, Belgium
| | - Kevin J Verstrepen
- Laboratory for Genetics and Genomics, Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Gaston Geenslaan 1, B-3001 Leuven, Belgium
- Laboratory for Systems Biology, VIB Center for Microbiology, Bio-Incubator, Gaston Geenslaan 1, 3001 Leuven, Belgium
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Morita K, Nomura Y, Ishii J, Matsuda F, Kondo A, Shimizu H. Heterologous expression of bacterial phosphoenol pyruvate carboxylase and Entner-Doudoroff pathway in Saccharomyces cerevisiae for improvement of isobutanol production. J Biosci Bioeng 2017; 124:263-270. [PMID: 28539187 DOI: 10.1016/j.jbiosc.2017.04.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 04/07/2017] [Indexed: 11/30/2022]
Abstract
Bacterial phosphoenol pyruvate carboxylase (PPC) and enzymes in the Entner-Doudoroff (ED) pathway were heterologously expressed in Saccharomyces cerevisiae to improve the NADPH supply required for the bio-production of chemicals such as isobutanol. The heterologous expression of PPC from Synechocystis sp. PCC6803 increased in the isobutabol titer 1.45-fold (93.2±1.6 mg/L) in metabolically engineered S. cerevisiae strains producing isobutanol. This result suggested that the pyruvate and NADPH supply for isobutanol biosynthesis was activated by PPC overexpression. On the other hand, the expression of two enzymes organizing the ED pathway (6-phosphogluconate dehydratase [6PGD] and 2-dehydro-3-deoxy-phosphogluconate aldolase [KDPGA]) had no effect to isobutabol bio-production. Further analysis, however, revealed that additional expression of 6PGD and KDPGA improved the growth rate of S. cerevisiae strain BY4742 gnd1Δ. A 13C-labeling experiment using [1-13C] glucose also suggested that metabolic flow levels in the ED pathway increased slightly with the additional expression. These results showed that the ED pathway was successfully constructed in S. cerevisiae, even though activity of the pathway was too weak to improve isobutanol biosynthesis.
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Affiliation(s)
- Keisuke Morita
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Yuta Nomura
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Jun Ishii
- Graduate School of Science, Technology, and Innovation, Kobe University, 1-1 Rokkodaicho, Nada, Kobe 657-8501, Japan.
| | - Fumio Matsuda
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Akihiko Kondo
- Graduate School of Science, Technology, and Innovation, Kobe University, 1-1 Rokkodaicho, Nada, Kobe 657-8501, Japan.
| | - Hiroshi Shimizu
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Nielsen JC, Nielsen J. Development of fungal cell factories for the production of secondary metabolites: Linking genomics and metabolism. Synth Syst Biotechnol 2017; 2:5-12. [PMID: 29062956 PMCID: PMC5625732 DOI: 10.1016/j.synbio.2017.02.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 02/06/2017] [Accepted: 02/07/2017] [Indexed: 12/01/2022] Open
Abstract
The genomic era has revolutionized research on secondary metabolites and bioinformatics methods have in recent years revived the antibiotic discovery process after decades with only few new active molecules being identified. New computational tools are driven by genomics and metabolomics analysis, and enables rapid identification of novel secondary metabolites. To translate this increased discovery rate into industrial exploitation, it is necessary to integrate secondary metabolite pathways in the metabolic engineering process. In this review, we will describe the novel advances in discovery of secondary metabolites produced by filamentous fungi, highlight the utilization of genome-scale metabolic models (GEMs) in the design of fungal cell factories for the production of secondary metabolites and review strategies for optimizing secondary metabolite production through the construction of high yielding platform cell factories.
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Affiliation(s)
| | - Jens Nielsen
- Chalmers University of Technology, Kemivägen 10, Sweden
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10
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Abstract
Alcohols (CnHn+2OH) are classified into primary, secondary, and tertiary alcohols, which can be branched or unbranched. They can also feature more than one OH-group (two OH-groups = diol; three OH-groups = triol). Presently, except for ethanol and sugar alcohols, they are mainly produced from fossil-based resources, such as petroleum, gas, and coal. Methanol and ethanol have the highest annual production volume accounting for 53 and 91 million tons/year, respectively. Most alcohols are used as fuels (e.g., ethanol), solvents (e.g., butanol), and chemical intermediates.This chapter gives an overview of recent research on the production of short-chain unbranched alcohols (C1-C5), focusing in particular on propanediols (1,2- and 1,3-propanediol), butanols, and butanediols (1,4- and 2,3-butanediol). It also provides a short summary on biobased higher alcohols (>C5) including branched alcohols.
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Development of Synthetic Microbial Platforms to Convert Lignocellulosic Biomass to Biofuels. ADVANCES IN BIOENERGY 2017. [DOI: 10.1016/bs.aibe.2016.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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12
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Liang M, Zhou X, Xu C. Systems biology in biofuel. PHYSICAL SCIENCES REVIEWS 2016. [DOI: 10.1515/psr-2016-0047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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13
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Heavner BD, Price ND. Comparative Analysis of Yeast Metabolic Network Models Highlights Progress, Opportunities for Metabolic Reconstruction. PLoS Comput Biol 2015; 11:e1004530. [PMID: 26566239 PMCID: PMC4643975 DOI: 10.1371/journal.pcbi.1004530] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 08/28/2015] [Indexed: 11/18/2022] Open
Abstract
We have compared 12 genome-scale models of the Saccharomyces cerevisiae metabolic network published since 2003 to evaluate progress in reconstruction of the yeast metabolic network. We compared the genomic coverage, overlap of annotated metabolites, predictive ability for single gene essentiality with a selection of model parameters, and biomass production predictions in simulated nutrient-limited conditions. We have also compared pairwise gene knockout essentiality predictions for 10 of these models. We found that varying approaches to model scope and annotation reflected the involvement of multiple research groups in model development; that single-gene essentiality predictions were affected by simulated medium, objective function, and the reference list of essential genes; and that predictive ability for single-gene essentiality did not correlate well with predictive ability for our reference list of synthetic lethal gene interactions (R = 0.159). We conclude that the reconstruction of the yeast metabolic network is indeed gradually improving through the iterative process of model development, and there remains great opportunity for advancing our understanding of biology through continued efforts to reconstruct the full biochemical reaction network that constitutes yeast metabolism. Additionally, we suggest that there is opportunity for refining the process of deriving a metabolic model from a metabolic network reconstruction to facilitate mechanistic investigation and discovery. This comparative study lays the groundwork for developing improved tools and formalized methods to quantitatively assess metabolic network reconstructions independently of any particular model application, which will facilitate ongoing efforts to advance our understanding of the relationship between genotype and cellular phenotype.
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Affiliation(s)
- Benjamin D. Heavner
- Institute for Systems Biology, Seattle, Washington, United States of America
| | - Nathan D. Price
- Institute for Systems Biology, Seattle, Washington, United States of America
- * E-mail:
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Abstract
Metabolic processes are altered in cancer cells, which obtain advantages from this metabolic reprogramming in terms of energy production and synthesis of biomolecules that sustain their uncontrolled proliferation. Due to the conceptual progresses in the last decade, metabolic reprogramming was recently included as one of the new hallmarks of cancer. The advent of high-throughput technologies to amass an abundance of omic data, together with the development of new computational methods that allow the integration and analysis of omic data by using genome-scale reconstructions of human metabolism, have increased and accelerated the discovery and development of anticancer drugs and tumor-specific metabolic biomarkers. Here we review and discuss the latest advances in the context of metabolic reprogramming and the future in cancer research.
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Horvat P, Koller M, Braunegg G. Recent advances in elementary flux modes and yield space analysis as useful tools in metabolic network studies. World J Microbiol Biotechnol 2015; 31:1315-28. [DOI: 10.1007/s11274-015-1887-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 06/05/2015] [Indexed: 11/25/2022]
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16
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Zhang C, Ji B, Mardinoglu A, Nielsen J, Hua Q. Logical transformation of genome-scale metabolic models for gene level applications and analysis. Bioinformatics 2015; 31:2324-31. [DOI: 10.1093/bioinformatics/btv134] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Accepted: 02/25/2015] [Indexed: 01/10/2023] Open
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Krivoruchko A, Zhang Y, Siewers V, Chen Y, Nielsen J. Microbial acetyl-CoA metabolism and metabolic engineering. Metab Eng 2014; 28:28-42. [PMID: 25485951 DOI: 10.1016/j.ymben.2014.11.009] [Citation(s) in RCA: 195] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2014] [Revised: 11/25/2014] [Accepted: 11/26/2014] [Indexed: 12/23/2022]
Abstract
Recent concerns over the sustainability of petrochemical-based processes for production of desired chemicals have fueled research into alternative modes of production. Metabolic engineering of microbial cell factories such as Saccharomyces cerevisiae and Escherichia coli offers a sustainable and flexible alternative for the production of various molecules. Acetyl-CoA is a key molecule in microbial central carbon metabolism and is involved in a variety of cellular processes. In addition, it functions as a precursor for many molecules of biotechnological relevance. Therefore, much interest exists in engineering the metabolism around the acetyl-CoA pools in cells in order to increase product titers. Here we provide an overview of the acetyl-CoA metabolism in eukaryotic and prokaryotic microbes (with a focus on S. cerevisiae and E. coli), with an emphasis on reactions involved in the production and consumption of acetyl-CoA. In addition, we review various strategies that have been used to increase acetyl-CoA production in these microbes.
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Affiliation(s)
- Anastasia Krivoruchko
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Yiming Zhang
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Verena Siewers
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Yun Chen
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Jens Nielsen
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.
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Lee NR, Lakshmanan M, Aggarwal S, Song JW, Karimi IA, Lee DY, Park JB. Genome-scale metabolic network reconstruction and in silico flux analysis of the thermophilic bacterium Thermus thermophilus HB27. Microb Cell Fact 2014; 13:61. [PMID: 24774833 PMCID: PMC4021367 DOI: 10.1186/1475-2859-13-61] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 04/17/2014] [Indexed: 01/18/2023] Open
Abstract
Background Thermus thermophilus, an extremely thermophilic bacterium, has been widely recognized as a model organism for studying how microbes can survive and adapt under high temperature environment. However, the thermotolerant mechanisms and cellular metabolism still remains mostly unravelled. Thus, it is highly required to consider systems biological approaches where T. thermophilus metabolic network model can be employed together with high throughput experimental data for elucidating its physiological characteristics under such harsh conditions. Results We reconstructed a genome-scale metabolic model of T. thermophilus, iTT548, the first ever large-scale network of a thermophilic bacterium, accounting for 548 unique genes, 796 reactions and 635 unique metabolites. Our initial comparative analysis of the model with Escherichia coli has revealed several distinctive metabolic reactions, mainly in amino acid metabolism and carotenoid biosynthesis, producing relevant compounds to retain the cellular membrane for withstanding high temperature. Constraints-based flux analysis was, then, applied to simulate the metabolic state in glucose minimal and amino acid rich media. Remarkably, resulting growth predictions were highly consistent with the experimental observations. The subsequent comparative flux analysis under different environmental conditions highlighted that the cells consumed branched chain amino acids preferably and utilized them directly in the relevant anabolic pathways for the fatty acid synthesis. Finally, gene essentiality study was also conducted via single gene deletion analysis, to identify the conditional essential genes in glucose minimal and complex media. Conclusions The reconstructed genome-scale metabolic model elucidates the phenotypes of T. thermophilus, thus allowing us to gain valuable insights into its cellular metabolism through in silico simulations. The information obtained from such analysis would not only shed light on the understanding of physiology of thermophiles but also helps us to devise metabolic engineering strategies to develop T. thermophilus as a thermostable microbial cell factory.
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Affiliation(s)
| | | | | | | | | | - Dong-Yup Lee
- Department of Food Science & Engineering, Ewha Womans University, 11-1 Daehyun-dong, Seodaemun-gu, Seoul 120-750, Korea.
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Si T, Luo Y, Xiao H, Zhao H. Utilizing an endogenous pathway for 1-butanol production in Saccharomyces cerevisiae. Metab Eng 2014; 22:60-8. [DOI: 10.1016/j.ymben.2014.01.002] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 12/02/2013] [Accepted: 01/02/2014] [Indexed: 01/13/2023]
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Ishii J, Kondo T, Makino H, Ogura A, Matsuda F, Kondo A. Three gene expression vector sets for concurrently expressing multiple genes inSaccharomyces cerevisiae. FEMS Yeast Res 2014; 14:399-411. [DOI: 10.1111/1567-1364.12138] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 11/08/2013] [Accepted: 01/15/2014] [Indexed: 01/25/2023] Open
Affiliation(s)
- Jun Ishii
- Organization of Advanced Science and Technology; Kobe University; Kobe Japan
| | - Takashi Kondo
- Organization of Advanced Science and Technology; Kobe University; Kobe Japan
| | - Harumi Makino
- Organization of Advanced Science and Technology; Kobe University; Kobe Japan
| | - Akira Ogura
- Organization of Advanced Science and Technology; Kobe University; Kobe Japan
| | - Fumio Matsuda
- Organization of Advanced Science and Technology; Kobe University; Kobe Japan
- RIKEN Biomass Engineering Program; Yokohama Japan
| | - Akihiko Kondo
- RIKEN Biomass Engineering Program; Yokohama Japan
- Department of Chemical Science and Engineering; Graduate School of Engineering; Kobe University; Kobe Japan
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Matsuda F, Ishii J, Kondo T, Ida K, Tezuka H, Kondo A. Increased isobutanol production in Saccharomyces cerevisiae by eliminating competing pathways and resolving cofactor imbalance. Microb Cell Fact 2013; 12:119. [PMID: 24305546 PMCID: PMC3866936 DOI: 10.1186/1475-2859-12-119] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 11/05/2013] [Indexed: 11/10/2022] Open
Abstract
Background Isobutanol is an important target for biorefinery research as a next-generation biofuel and a building block for commodity chemical production. Metabolically engineered microbial strains to produce isobutanol have been successfully developed by introducing the Ehrlich pathway into bacterial hosts. Isobutanol-producing baker’s yeast (Saccharomyces cerevisiae) strains have been developed following the strategy with respect to its advantageous characteristics for cost-effective isobutanol production. However, the isobutanol yields and titers attained by the developed strains need to be further improved through engineering of S. cerevisiae metabolism. Results Two strategies including eliminating competing pathways and resolving the cofactor imbalance were applied to improve isobutanol production in S. cerevisiae. Isobutanol production levels were increased in strains lacking genes encoding members of the pyruvate dehydrogenase complex such as LPD1, indicating that the pyruvate supply for isobutanol biosynthesis is competing with acetyl-CoA biosynthesis in mitochondria. Isobutanol production was increased by overexpression of enzymes responsible for transhydrogenase-like shunts such as pyruvate carboxylase, malate dehydrogenase, and malic enzyme. The integration of a single gene deletion lpd1Δ and the activation of the transhydrogenase-like shunt further increased isobutanol levels. In a batch fermentation test at the 50-mL scale from 100 g/L glucose using the two integrated strains, the isobutanol titer reached 1.62 ± 0.11 g/L and 1.61 ± 0.03 g/L at 24 h after the start of fermentation, which corresponds to the yield at 0.016 ± 0.001 g/g glucose consumed and 0.016 ± 0.0003 g/g glucose consumed, respectively. Conclusions These results demonstrate that downregulation of competing pathways and metabolic functions for resolving the cofactor imbalance are promising strategies to construct S. cerevisiae strains that effectively produce isobutanol.
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Affiliation(s)
| | | | | | | | | | - Akihiko Kondo
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehirocho, Turumi-ku, Yokohama, Kanagawa 230-0045, Japan.
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Ammar EM, Wang Z, Yang ST. Metabolic engineering of Propionibacterium freudenreichii for n-propanol production. Appl Microbiol Biotechnol 2013; 97:4677-90. [PMID: 23576036 DOI: 10.1007/s00253-013-4861-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Revised: 03/11/2013] [Accepted: 03/13/2013] [Indexed: 11/25/2022]
Abstract
Propionibacteria are widely used in industry for manufacturing of Swiss cheese, vitamin B₁₂, and propionic acid. However, little is known about their genetics and only a few reports are available on the metabolic engineering of propionibacteria aiming at enhancing fermentative production of vitamin B12 and propionic acid. n-Propanol is a common solvent, an intermediate in many industrial applications, and a promising biofuel. To date, no wild-type microorganism is known to produce n-propanol in sufficient quantities for industrial application purposes. In this study, a bifunctional aldehyde/alcohol dehydrogenase (adhE) was cloned from Escherichia coli and expressed in Propionibacterium freudenreichii. The mutants expressing the adhE gene converted propionyl- coenzyme A, which is the precursor for propionic acid biosynthesis, to n-propanol. The production of n-propanol was limited by NADH availability, which was improved significantly by using glycerol as the carbon source. Interestingly, the improved propanol production was accompanied by a significant increase in propionic acid productivity, indicating a positive effect of n-propanol biosynthesis on propionic acid fermentative production. To our best knowledge, this is the first report on producing n-propanol by metabolically engineered propionibacteria, which offers a novel route to produce n-propanol from renewable feedstock, and possibly a new way to boost propionic acid fermentation.
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Affiliation(s)
- Ehab Mohamed Ammar
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, 140 West 19th Avenue, Columbus, OH 43210, USA
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Kondo A, Ishii J, Hara KY, Hasunuma T, Matsuda F. Development of microbial cell factories for bio-refinery through synthetic bioengineering. J Biotechnol 2013; 163:204-16. [DOI: 10.1016/j.jbiotec.2012.05.021] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 05/10/2012] [Accepted: 05/18/2012] [Indexed: 12/24/2022]
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Bankar SB, Survase SA, Ojamo H, Granström T. Biobutanol: the outlook of an academic and industrialist. RSC Adv 2013. [DOI: 10.1039/c3ra43011a] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Leprince A, van Passel MWJ, dos Santos VAPM. Streamlining genomes: toward the generation of simplified and stabilized microbial systems. Curr Opin Biotechnol 2012; 23:651-8. [DOI: 10.1016/j.copbio.2012.05.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 05/01/2012] [Accepted: 05/02/2012] [Indexed: 02/07/2023]
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Li S, Huang D, Li Y, Wen J, Jia X. Rational improvement of the engineered isobutanol-producing Bacillus subtilis by elementary mode analysis. Microb Cell Fact 2012; 11:101. [PMID: 22862776 PMCID: PMC3475101 DOI: 10.1186/1475-2859-11-101] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 07/13/2012] [Indexed: 01/08/2023] Open
Abstract
Background Isobutanol is considered as a leading candidate for the replacement of current fossil fuels, and expected to be produced biotechnologically. Owing to the valuable features, Bacillus subtilis has been engineered as an isobutanol producer, whereas it needs to be further optimized for more efficient production. Since elementary mode analysis (EMA) is a powerful tool for systematical analysis of metabolic network structures and cell metabolism, it might be of great importance in the rational strain improvement. Results Metabolic network of the isobutanol-producing B. subtilis BSUL03 was first constructed for EMA. Considering the actual cellular physiological state, 239 elementary modes (EMs) were screened from total 11,342 EMs for potential target prediction. On this basis, lactate dehydrogenase (LDH) and pyruvate dehydrogenase complex (PDHC) were predicted as the most promising inactivation candidates according to flux flexibility analysis and intracellular flux distribution simulation. Then, the in silico designed mutants were experimentally constructed. The maximal isobutanol yield of the LDH- and PDHC-deficient strain BSUL05 reached 61% of the theoretical value to 0.36 ± 0.02 C-mol isobutanol/C-mol glucose, which was 2.3-fold of BSUL03. Moreover, this mutant produced approximately 70 % more isobutanol to the maximal titer of 5.5 ± 0.3 g/L in fed-batch fermentations. Conclusions EMA was employed as a guiding tool to direct rational improvement of the engineered isobutanol-producing B. subtilis. The consistency between model prediction and experimental results demonstrates the rationality and accuracy of this EMA-based approach for target identification. This network-based rational strain improvement strategy could serve as a promising concept to engineer efficient B. subtilis hosts for isobutanol, as well as other valuable products.
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Affiliation(s)
- Shanshan Li
- Department of Biological Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
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27
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Systems biology of yeast: enabling technology for development of cell factories for production of advanced biofuels. Curr Opin Biotechnol 2012; 23:624-30. [DOI: 10.1016/j.copbio.2011.11.021] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Revised: 11/16/2011] [Accepted: 11/17/2011] [Indexed: 01/22/2023]
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Implementation of a transhydrogenase-like shunt to counter redox imbalance during xylose fermentation in Saccharomyces cerevisiae. Appl Microbiol Biotechnol 2012; 97:1669-78. [PMID: 22851014 DOI: 10.1007/s00253-012-4298-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 07/10/2012] [Accepted: 07/11/2012] [Indexed: 01/10/2023]
Abstract
Three enzymes responsible for the transhydrogenase-like shunt, including malic enzyme (encoded by MAE1), malate dehydrogenase (MDH2), and pyruvate carboxylase (PYC2), were overexpressed to regulate the redox state in xylose-fermenting recombinant Saccharomyces cerevisiae. The YPH499XU/MAE1 strain was constructed by overexpressing native Mae1p in the YPH499XU strain expressing xylose reductase and xylitol dehydrogenase from Scheffersomyces stipitis, and native xylulokinase. Analysis of the xylose fermentation profile under semi-anaerobic conditions revealed that the ethanol yield in the YPH499XU/MAE1 strain (0.38 ± 0.01 g g⁻¹ xylose consumed) was improved from that of the control strain (0.31 ± 0.01 g g⁻¹ xylose consumed). Reduced xylitol production was also observed in YPH499XU/MAE1, suggesting that the redox balance was altered by Mae1p overexpression. Analysis of intracellular metabolites showed that the redox imbalance during xylose fermentation was partly relieved in the transformant. The specific ethanol production rate in the YPH499XU/MAE1-MDH2 strain was 1.25-fold higher than that of YPH499XU/MAE1 due to the additional overexpression of Mdh2p, whereas the ethanol yield was identical to that of YPH499XU/MAE1. The specific xylose consumption rate was drastically increased in the YPH499XU/MAE1-MDH2-PYC2 strain. However, poor ethanol yield as well as increased production of xylitol was observed. These results demonstrate that the transhydrogenase function implemented in S. cerevisiae can regulate the redox state of yeast cells.
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Ng CY, Jung MY, Lee J, Oh MK. Production of 2,3-butanediol in Saccharomyces cerevisiae by in silico aided metabolic engineering. Microb Cell Fact 2012; 11:68. [PMID: 22640729 PMCID: PMC3442981 DOI: 10.1186/1475-2859-11-68] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 05/04/2012] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND 2,3-Butanediol is a chemical compound of increasing interest due to its wide applications. It can be synthesized via mixed acid fermentation of pathogenic bacteria such as Enterobacter aerogenes and Klebsiella oxytoca. The non-pathogenic Saccharomyces cerevisiae possesses three different 2,3-butanediol biosynthetic pathways, but produces minute amount of 2,3-butanediol. Hence, we attempted to engineer S. cerevisiae strain to enhance 2,3-butanediol production. RESULTS We first identified gene deletion strategy by performing in silico genome-scale metabolic analysis. Based on the best in silico strategy, in which disruption of alcohol dehydrogenase (ADH) pathway is required, we then constructed gene deletion mutant strains and performed batch cultivation of the strains. Deletion of three ADH genes, ADH1, ADH3 and ADH5, increased 2,3-butanediol production by 55-fold under microaerobic condition. However, overproduction of glycerol was observed in this triple deletion strain. Additional rational design to reduce glycerol production by GPD2 deletion altered the carbon fluxes back to ethanol and significantly reduced 2,3-butanediol production. Deletion of ALD6 reduced acetate production in strains lacking major ADH isozymes, but it did not favor 2,3-butanediol production. Finally, we introduced 2,3-butanediol biosynthetic pathway from Bacillus subtilis and E. aerogenes to the engineered strain and successfully increased titer and yield. Highest 2,3-butanediol titer (2.29 . l-1) and yield (0.113 g . g-1) were achieved by Δadh1 Δadh3 Δadh5 strain under anaerobic condition. CONCLUSIONS With the aid of in silico metabolic engineering, we have successfully designed and constructed S. cerevisiae strains with improved 2,3-butanediol production.
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Affiliation(s)
- Chiam Yu Ng
- Department of Chemical & Biological Engineering, Korea University, Seoul 136-701, Republic of Korea
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30
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Kato H, Izumi Y, Hasunuma T, Matsuda F, Kondo A. Widely targeted metabolic profiling analysis of yeast central metabolites. J Biosci Bioeng 2012; 113:665-73. [DOI: 10.1016/j.jbiosc.2011.12.013] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Revised: 12/09/2011] [Accepted: 12/25/2011] [Indexed: 11/26/2022]
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Kondo T, Tezuka H, Ishii J, Matsuda F, Ogino C, Kondo A. Genetic engineering to enhance the Ehrlich pathway and alter carbon flux for increased isobutanol production from glucose by Saccharomyces cerevisiae. J Biotechnol 2012; 159:32-7. [DOI: 10.1016/j.jbiotec.2012.01.022] [Citation(s) in RCA: 133] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 12/23/2011] [Accepted: 01/19/2012] [Indexed: 11/17/2022]
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Shi S, Valle-Rodríguez JO, Khoomrung S, Siewers V, Nielsen J. Functional expression and characterization of five wax ester synthases in Saccharomyces cerevisiae and their utility for biodiesel production. BIOTECHNOLOGY FOR BIOFUELS 2012; 5:7. [PMID: 22364438 PMCID: PMC3309958 DOI: 10.1186/1754-6834-5-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 02/24/2012] [Indexed: 05/24/2023]
Abstract
BACKGROUND Wax ester synthases (WSs) can synthesize wax esters from alcohols and fatty acyl coenzyme A thioesters. The knowledge of the preferred substrates for each WS allows the use of yeast cells for the production of wax esters that are high-value materials and can be used in a variety of industrial applications. The products of WSs include fatty acid ethyl esters, which can be directly used as biodiesel. RESULTS Here, heterologous WSs derived from five different organisms were successfully expressed and evaluated for their substrate preference in Saccharomyces cerevisiae. We investigated the potential of the different WSs for biodiesel (that is, fatty acid ethyl esters) production in S. cerevisiae. All investigated WSs, from Acinetobacter baylyi ADP1, Marinobacter hydrocarbonoclasticus DSM 8798, Rhodococcus opacus PD630, Mus musculus C57BL/6 and Psychrobacter arcticus 273-4, have different substrate specificities, but they can all lead to the formation of biodiesel. The best biodiesel producing strain was found to be the one expressing WS from M. hydrocarbonoclasticus DSM 8798 that resulted in a biodiesel titer of 6.3 mg/L. To further enhance biodiesel production, acetyl coenzyme A carboxylase was up-regulated, which resulted in a 30% increase in biodiesel production. CONCLUSIONS Five WSs from different species were functionally expressed and their substrate preference characterized in S. cerevisiae, thus constructing cell factories for the production of specific kinds of wax ester. WS from M. hydrocarbonoclasticus showed the highest preference for ethanol compared to the other WSs, and could permit the engineered S. cerevisiae to produce biodiesel.
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Affiliation(s)
- Shuobo Shi
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Kemivägen 10, SE 412 96, Göteborg, Sweden
| | - Juan Octavio Valle-Rodríguez
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Kemivägen 10, SE 412 96, Göteborg, Sweden
| | - Sakda Khoomrung
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Kemivägen 10, SE 412 96, Göteborg, Sweden
| | - Verena Siewers
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Kemivägen 10, SE 412 96, Göteborg, Sweden
| | - Jens Nielsen
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Kemivägen 10, SE 412 96, Göteborg, Sweden
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Shi S, Valle-Rodríguez JO, Khoomrung S, Siewers V, Nielsen J. Functional expression and characterization of five wax ester synthases in Saccharomyces cerevisiae and their utility for biodiesel production. BIOTECHNOLOGY FOR BIOFUELS 2012. [PMID: 22364438 DOI: 10.1186/preaccept-1932279820621895] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
BACKGROUND Wax ester synthases (WSs) can synthesize wax esters from alcohols and fatty acyl coenzyme A thioesters. The knowledge of the preferred substrates for each WS allows the use of yeast cells for the production of wax esters that are high-value materials and can be used in a variety of industrial applications. The products of WSs include fatty acid ethyl esters, which can be directly used as biodiesel. RESULTS Here, heterologous WSs derived from five different organisms were successfully expressed and evaluated for their substrate preference in Saccharomyces cerevisiae. We investigated the potential of the different WSs for biodiesel (that is, fatty acid ethyl esters) production in S. cerevisiae. All investigated WSs, from Acinetobacter baylyi ADP1, Marinobacter hydrocarbonoclasticus DSM 8798, Rhodococcus opacus PD630, Mus musculus C57BL/6 and Psychrobacter arcticus 273-4, have different substrate specificities, but they can all lead to the formation of biodiesel. The best biodiesel producing strain was found to be the one expressing WS from M. hydrocarbonoclasticus DSM 8798 that resulted in a biodiesel titer of 6.3 mg/L. To further enhance biodiesel production, acetyl coenzyme A carboxylase was up-regulated, which resulted in a 30% increase in biodiesel production. CONCLUSIONS Five WSs from different species were functionally expressed and their substrate preference characterized in S. cerevisiae, thus constructing cell factories for the production of specific kinds of wax ester. WS from M. hydrocarbonoclasticus showed the highest preference for ethanol compared to the other WSs, and could permit the engineered S. cerevisiae to produce biodiesel.
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Affiliation(s)
- Shuobo Shi
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Kemivägen 10, SE 412 96, Göteborg, Sweden.
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Trinh CT, Thompson RA. Elementary mode analysis: a useful metabolic pathway analysis tool for reprograming microbial metabolic pathways. Subcell Biochem 2012; 64:21-42. [PMID: 23080244 DOI: 10.1007/978-94-007-5055-5_2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Elementary mode analysis is a useful metabolic pathway analysis tool to characterize cellular metabolism. It can identify all feasible metabolic pathways known as elementary modes that are inherent to a metabolic network. Each elementary mode contains a minimal and unique set of enzymatic reactions that can support cellular functions at steady state. Knowledge of all these pathway options enables systematic characterization of cellular phenotypes, analysis of metabolic network properties (e.g. structure, regulation, robustness, and fragility), phenotypic behavior discovery, and rational strain design for metabolic engineering application. This chapter focuses on the application of elementary mode analysis to reprogram microbial metabolic pathways for rational strain design and the metabolic pathway evolution of designed strains.
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Affiliation(s)
- Cong T Trinh
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN, USA,
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