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Karpe AV, Beale DJ, Tran CD. Intelligent Biological Networks: Improving Anti-Microbial Resistance Resilience through Nutritional Interventions to Understand Protozoal Gut Infections. Microorganisms 2023; 11:1800. [PMID: 37512972 PMCID: PMC10383877 DOI: 10.3390/microorganisms11071800] [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: 05/31/2023] [Revised: 07/10/2023] [Accepted: 07/11/2023] [Indexed: 07/30/2023] Open
Abstract
Enteric protozoan pathogenic infections significantly contribute to the global burden of gastrointestinal illnesses. Their occurrence is considerable within remote and indigenous communities and regions due to reduced access to clean water and adequate sanitation. The robustness of these pathogens leads to a requirement of harsh treatment methods, such as medicinal drugs or antibiotics. However, in addition to protozoal infection itself, these treatments impact the gut microbiome and create dysbiosis. This often leads to opportunistic pathogen invasion, anti-microbial resistance, or functional gastrointestinal disorders, such as irritable bowel syndrome. Moreover, these impacts do not remain confined to the gut and are reflected across the gut-brain, gut-liver, and gut-lung axes, among others. Therefore, apart from medicinal treatment, nutritional supplementation is also a key aspect of providing recovery from this dysbiosis. Future proteins, prebiotics, probiotics, synbiotics, and food formulations offer a good solution to remedy this dysbiosis. Furthermore, nutritional supplementation also helps to build resilience against opportunistic pathogens and potential future infections and disorders that may arise due to the dysbiosis. Systems biology techniques have shown to be highly effective tools to understand the biochemistry of these processes. Systems biology techniques characterize the fundamental host-pathogen interaction biochemical pathways at various infection and recovery stages. This same mechanism also allows the impact of the abovementioned treatment methods of gut microbiome remediation to be tracked. This manuscript discusses system biology approaches, analytical techniques, and interaction and association networks, to understand (1) infection mechanisms and current global status; (2) cross-organ impacts of dysbiosis, particularly within the gut-liver and gut-lung axes; and (3) nutritional interventions. This study highlights the impact of anti-microbial resistance and multi-drug resistance from the perspective of protozoal infections. It also highlights the role of nutritional interventions to add resilience against the chronic problems caused by these phenomena.
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Affiliation(s)
- Avinash V Karpe
- Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation, Black Mountain Science and Innovation Park, Acton, ACT 2601, Australia
- Socio-Eternal Thinking for Unity (SETU), Melbourne, VIC 3805, Australia
| | - David J Beale
- Environment, Commonwealth Scientific and Industrial Research Organisation, Ecosciences Precinct, Dutton Park, QLD 4102, Australia
| | - Cuong D Tran
- Health and Biosecurity, Commonwealth Scientific and Industrial Research Organisation, Gate 13 Kintore Ave., Adelaide, SA 5000, Australia
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2
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Li L, Tian Y. The role of metabolic reprogramming of tumor-associated macrophages in shaping the immunosuppressive tumor microenvironment. Biomed Pharmacother 2023; 161:114504. [PMID: 37002579 DOI: 10.1016/j.biopha.2023.114504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 03/04/2023] [Accepted: 03/07/2023] [Indexed: 03/15/2023] Open
Abstract
Macrophages are potent immune effector cells in innate immunity and exert dual-effects in the tumor microenvironment (TME). Tumor-associated macrophages (TAMs) make up a significant portion of TME immune cells. Similar to M1/M2 macrophages, TAMs are also highly plastic, and their functions are regulated by cytokines, chemokines and other factors in the TME. The metabolic changes in TAMs are significantly associated with polarization towards a protumour or antitumour phenotype. The metabolites generated via TAM metabolic reprogramming in turn promote tumor progression and immune tolerance. In this review, we explore the metabolic reprogramming of TAMs in terms of energy, amino acid and fatty acid metabolism and the potential roles of these changes in immune suppression.
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Affiliation(s)
- Lunxu Li
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yu Tian
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, China.
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Borin GP, Oliveira JVDC. Assessing the intracellular primary metabolic profile of Trichoderma reesei and Aspergillus niger grown on different carbon sources. FRONTIERS IN FUNGAL BIOLOGY 2022; 3:998361. [PMID: 37746225 PMCID: PMC10512294 DOI: 10.3389/ffunb.2022.998361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 08/29/2022] [Indexed: 09/26/2023]
Abstract
Trichoderma reesei and Aspergillus niger are efficient biological platforms for the production of various industrial products, including cellulases and organic acids. Nevertheless, despite the extensive research on these fungi, integrated analyses of omics-driven approaches are still missing. In this study, the intracellular metabolic profile of T. reesei RUT-C30 and A. niger N402 strains grown on glucose, lactose, carboxymethylcellulose (CMC), and steam-exploded sugarcane bagasse (SEB) as carbon sources for 48 h was analysed by proton nuclear magnetic resonance. The aim was to verify the changes in the primary metabolism triggered by these substrates and use transcriptomics data from the literature to better understand the dynamics of the observed alterations. Glucose and CMC induced higher fungal growth whereas fungi grown on lactose showed the lowest dry weight. Metabolic profile analysis revealed that mannitol, trehalose, glutamate, glutamine, and alanine were the most abundant metabolites in both fungi regardless of the carbon source. These metabolites are of particular interest for the mobilization of carbon and nitrogen, and stress tolerance inside the cell. Their concomitant presence indicates conserved mechanisms adopted by both fungi to assimilate carbon sources of different levels of recalcitrance. Moreover, the higher levels of galactose intermediates in T. reesei suggest its better adaptation in lactose, whereas glycolate and malate in CMC might indicate activation of the glyoxylate shunt. Glycerol and 4-aminobutyrate accumulated in A. niger grown on CMC and lactose, suggesting their relevant role in these carbon sources. In SEB, a lower quantity and diversity of metabolites were identified compared to the other carbon sources, and the metabolic changes and higher xylanase and pNPGase activities indicated a better utilization of bagasse by A. niger. Transcriptomic analysis supported the observed metabolic changes and pathways identified in this work. Taken together, we have advanced the knowledge about how fungal primary metabolism is affected by different carbon sources, and have drawn attention to metabolites still unexplored. These findings might ultimately be considered for developing more robust and efficient microbial factories.
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Affiliation(s)
- Gustavo Pagotto Borin
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), São Paulo, Brazil
- Graduate Program in Genetics and Molecular Biology, Institute of Biology, University of Campinas (UNICAMP), São Paulo, Brazil
| | - Juliana Velasco de Castro Oliveira
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), São Paulo, Brazil
- Graduate Program in Genetics and Molecular Biology, Institute of Biology, University of Campinas (UNICAMP), São Paulo, Brazil
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Kubisch C, Kövilein A, Aliyu H, Ochsenreither K. RNA-Seq Based Transcriptome Analysis of Aspergillus oryzae DSM 1863 Grown on Glucose, Acetate and an Aqueous Condensate from the Fast Pyrolysis of Wheat Straw. J Fungi (Basel) 2022; 8:jof8080765. [PMID: 35893132 PMCID: PMC9394295 DOI: 10.3390/jof8080765] [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: 06/23/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 11/16/2022] Open
Abstract
Due to its acetate content, the pyrolytic aqueous condensate (PAC) formed during the fast pyrolysis of wheat straw could provide an inexpensive substrate for microbial fermentation. However, PAC also contains several inhibitors that make its detoxification inevitable. In our study, we examined the transcriptional response of Aspergillus oryzae to cultivation on 20% detoxified PAC, pure acetate and glucose using RNA-seq analysis. Functional enrichment analysis of 3463 significantly differentially expressed (log2FC >2 & FDR < 0.05) genes revealed similar metabolic tendencies for both acetate and PAC, as upregulated genes in these cultures were mainly associated with ribosomes and RNA processing, whereas transmembrane transport was downregulated. Unsurprisingly, metabolic pathway analysis revealed that glycolysis/gluconeogenesis and starch and sucrose metabolism were upregulated for glucose, whereas glyoxylate and the tricarboxylic acid (TCA) cycle were important carbon utilization pathways for acetate and PAC, respectively. Moreover, genes involved in the biosynthesis of various amino acids such as arginine, serine, cysteine and tryptophan showed higher expression in the acetate-containing cultures. Direct comparison of the transcriptome profiles of acetate and PAC revealed that pyruvate metabolism was the only significantly different metabolic pathway and was overexpressed in the PAC cultures. Upregulated genes included those for methylglyoxal degradation and alcohol dehydrogenases, which thus represent potential targets for the further improvement of fungal PAC tolerance.
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Wei Z, Xu Y, Xu Q, Cao W, Huang H, Liu H. Microbial Biosynthesis of L-Malic Acid and Related Metabolic Engineering Strategies: Advances and Prospects. Front Bioeng Biotechnol 2021; 9:765685. [PMID: 34660563 PMCID: PMC8511312 DOI: 10.3389/fbioe.2021.765685] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 09/16/2021] [Indexed: 11/13/2022] Open
Abstract
Malic acid, a four-carbon dicarboxylic acid, is widely used in the food, chemical and medical industries. As an intermediate of the TCA cycle, malic acid is one of the most promising building block chemicals that can be produced from renewable sources. To date, chemical synthesis or enzymatic conversion of petrochemical feedstocks are still the dominant mode for malic acid production. However, with increasing concerns surrounding environmental issues in recent years, microbial fermentation for the production of L-malic acid was extensively explored as an eco-friendly production process. The rapid development of genetic engineering has resulted in some promising strains suitable for large-scale bio-based production of malic acid. This review offers a comprehensive overview of the most recent developments, including a spectrum of wild-type, mutant, laboratory-evolved and metabolically engineered microorganisms for malic acid production. The technological progress in the fermentative production of malic acid is presented. Metabolic engineering strategies for malic acid production in various microorganisms are particularly reviewed. Biosynthetic pathways, transport of malic acid, elimination of byproducts and enhancement of metabolic fluxes are discussed and compared as strategies for improving malic acid production, thus providing insights into the current state of malic acid production, as well as further research directions for more efficient and economical microbial malic acid production.
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Affiliation(s)
- Zhen Wei
- MOE Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China
| | - Yongxue Xu
- MOE Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China
| | - Qing Xu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Wei Cao
- MOE Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China.,Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin University of Science & Technology, Tianjin, China
| | - He Huang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Hao Liu
- MOE Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China.,Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin University of Science & Technology, Tianjin, China
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Xue X, Bi F, Liu B, Li J, Zhang L, Zhang J, Gao Q, Wang D. Improving citric acid production of an industrial Aspergillus niger CGMCC 10142: identification and overexpression of a high-affinity glucose transporter with different promoters. Microb Cell Fact 2021; 20:168. [PMID: 34446025 PMCID: PMC8394697 DOI: 10.1186/s12934-021-01659-3] [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: 10/31/2020] [Accepted: 08/14/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Glucose transporters play an important role in the fermentation of citric acid. In this study, a high-affinity glucose transporter (HGT1) was identified and overexpressed in the industrial strain A. niger CGMCC 10142. HGT1-overexpressing strains using the PglaA and Paox1 promoters were constructed to verify the glucose transporter functions. RESULT As hypothesized, the HGT1-overexpressing strains showed higher citric acid production and lower residual sugar contents. The best-performing strain A. niger 20-15 exhibited a reduction of the total sugar content and residual reducing sugars by 16.5 and 44.7%, while the final citric acid production was significantly increased to 174.1 g/L, representing a 7.3% increase compared to A. niger CGMCC 10142. Measurement of the mRNA expression levels of relevant genes at different time-points during the fermentation indicated that in addition to HGT1, citrate synthase and glucokinase were also expressed at higher levels in the overexpression strains. CONCLUSION The results indicate that HGT1 overexpression resolved the metabolic bottleneck caused by insufficient sugar transport and thereby improved the sugar utilization rate. This study demonstrates the usefulness of the high-affinity glucose transporter HGT1 for improving the citric acid fermentation process of Aspergillus niger CGMCC 10142.
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Affiliation(s)
- Xianli Xue
- Key Laboratory of Industrial Microbiology & Engineering Research Center of Food Biotechnology of Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China
| | - Futi Bi
- Key Laboratory of Industrial Microbiology & Engineering Research Center of Food Biotechnology of Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China.,Tianjin Key Laboratory of Industrial Fermentation Microbiology, Tianjin, 300457, People's Republic of China
| | - Boya Liu
- Key Laboratory of Industrial Microbiology & Engineering Research Center of Food Biotechnology of Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China.,Tianjin Key Laboratory of Industrial Fermentation Microbiology, Tianjin, 300457, People's Republic of China
| | - Jie Li
- Key Laboratory of Industrial Microbiology & Engineering Research Center of Food Biotechnology of Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China
| | - Lan Zhang
- Key Laboratory of Industrial Microbiology & Engineering Research Center of Food Biotechnology of Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China
| | - Jian Zhang
- Key Laboratory of Industrial Microbiology & Engineering Research Center of Food Biotechnology of Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China
| | - Qiang Gao
- Key Laboratory of Industrial Microbiology & Engineering Research Center of Food Biotechnology of Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China
| | - Depei Wang
- Key Laboratory of Industrial Microbiology & Engineering Research Center of Food Biotechnology of Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China. .,Tianjin Key Laboratory of Industrial Fermentation Microbiology, Tianjin, 300457, People's Republic of China. .,Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin, 300457, People's Republic of China.
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Yamamoto N, Watarai N, Koyano H, Sawada K, Toyoda A, Kurokawa K, Yamada T. Analysis of genomic characteristics and their influence on metabolism in Aspergillus luchuensis albino mutants using genome sequencing. Fungal Genet Biol 2021; 155:103601. [PMID: 34224861 DOI: 10.1016/j.fgb.2021.103601] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 10/21/2022]
Abstract
Black Aspergillus luchuensis and its white albino mutant are essential fungi for making alcoholic beverages in Japan. A large number of industrial strains have been created using novel isolation or gene/genome mutation techniques. Such mutations influence metabolic and phenotypic characteristics in industrial strains, but few comparative studies of inter-strain mutation have been conducted. We carried out comparative genome analyses of 8 industrial strains of A. luchuensis and A. kawachii IFO 4308, the latter being the first albino strain to be isolated. Phylogenetic analysis based on 8938 concatenated genes exposed the diversity of black koji strains and uniformity among albino industrial strains, suggesting that passaged industrial albino strains have more genetic mutations compared with strain IFO 4308 and black koji strains. Comparative analysis showed that the albino strains had mutations in genes not only for conidial pigmentation but also in those that encode N-terminal acetyltransferase A and annexin XIV-like protein. The results also suggest that some mutations may have emerged through subculturing of albino strains. For example, mutations in the genes for isocitrate lyase and sugar transporters were observed only in industrial albino strains. This implies that selective pressure for increasing enzyme activity or secondary metabolites may have influenced the mutation of genes associated with environmental stress responses in A. luchuensis albino strains. Our study clarifies hitherto unknown genetic and metabolic characteristics of A. luchuensis industrial strains and provides potential applications for comparative genome analysis for breeding koji strains.
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Affiliation(s)
- Nozomi Yamamoto
- Department of Life Science and Technology, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Naoki Watarai
- Department of Life Science and Technology, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Hitoshi Koyano
- Department of Life Science and Technology, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Kazunori Sawada
- Corporate Strategy Office, Gurunavi, Inc., Toho Hibiya Building, 1-2-2 Yurakucho, Chiyoda-ku, Tokyo 100-0006, Japan
| | - Atsushi Toyoda
- Department of Genomics and Evolutionary Biology, National Institute of Genetics, Yata 1111, Mishima, Shizuoka 411-8540, Japan
| | - Ken Kurokawa
- Department of Informatics, National Institute of Genetics, Yata 1111, Mishima, Shizuoka 411-8540, Japan
| | - Takuji Yamada
- Department of Life Science and Technology, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550, Japan.
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Yang L, Henriksen MM, Hansen RS, Lübeck M, Vang J, Andersen JE, Bille S, Lübeck PS. Metabolic engineering of Aspergillus niger via ribonucleoprotein-based CRISPR-Cas9 system for succinic acid production from renewable biomass. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:206. [PMID: 33317620 PMCID: PMC7737382 DOI: 10.1186/s13068-020-01850-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 12/04/2020] [Indexed: 05/02/2023]
Abstract
BACKGROUND Succinic acid has great potential to be a new bio-based building block for deriving a number of value-added chemicals in industry. Bio-based succinic acid production from renewable biomass can provide a feasible approach to partially alleviate the dependence of global manufacturing on petroleum refinery. To improve the economics of biological processes, we attempted to explore possible solutions with a fungal cell platform. In this study, Aspergillus niger, a well-known industrial production organism for bio-based organic acids, was exploited for its potential for succinic acid production. RESULTS With a ribonucleoprotein (RNP)-based CRISPR-Cas9 system, consecutive genetic manipulations were realized in engineering of the citric acid-producing strain A. niger ATCC 1015. Two genes involved in production of two byproducts, gluconic acid and oxalic acid, were disrupted. In addition, an efficient C4-dicarboxylate transporter and a soluble NADH-dependent fumarate reductase were overexpressed. The resulting strain SAP-3 produced 17 g/L succinic acid while there was no succinic acid detected at a measurable level in the wild-type strain using a synthetic substrate. Furthermore, two cultivation parameters, temperature and pH, were investigated for their effects on succinic acid production. The highest amount of succinic acid was obtained at 35 °C after 3 days, and low culture pH had inhibitory effects on succinic acid production. Two types of renewable biomass were explored as substrates for succinic acid production. After 6 days, the SAP-3 strain was capable of producing 23 g/L and 9 g/L succinic acid from sugar beet molasses and wheat straw hydrolysate, respectively. CONCLUSIONS In this study, we have successfully applied the RNP-based CRISPR-Cas9 system in genetic engineering of A. niger and significantly improved the succinic acid production in the engineered strain. The studies on cultivation parameters revealed the impacts of pH and temperature on succinic acid production and the future challenges in strain development. The feasibility of using renewable biomass for succinic acid production by A. niger has been demonstrated with molasses and wheat straw hydrolysate.
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Affiliation(s)
- Lei Yang
- Section for Sustainable Biotechnology, Department of Chemistry and Bioscience, Aalborg University Copenhagen, A. C. Meyers Vænge 15, 2450, Copenhagen SV, Denmark.
| | - Mikkel Møller Henriksen
- Section for Sustainable Biotechnology, Department of Chemistry and Bioscience, Aalborg University Copenhagen, A. C. Meyers Vænge 15, 2450, Copenhagen SV, Denmark
| | - Rasmus Syrach Hansen
- Section for Sustainable Biotechnology, Department of Chemistry and Bioscience, Aalborg University Copenhagen, A. C. Meyers Vænge 15, 2450, Copenhagen SV, Denmark
| | - Mette Lübeck
- Section for Sustainable Biotechnology, Department of Chemistry and Bioscience, Aalborg University Copenhagen, A. C. Meyers Vænge 15, 2450, Copenhagen SV, Denmark
| | - Jesper Vang
- Section for Sustainable Biotechnology, Department of Chemistry and Bioscience, Aalborg University Copenhagen, A. C. Meyers Vænge 15, 2450, Copenhagen SV, Denmark
- Disease Data Intelligence, Department of Health Technology Bioinformatics, Technical University of Denmark, Bldg. 208, 2800, KemitorvetKgs. Lyngby, Denmark
| | - Julie Egelund Andersen
- Section of Microbiology, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark
| | - Signe Bille
- Section of Cell and Neurobiology, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark
| | - Peter Stephensen Lübeck
- Section for Sustainable Biotechnology, Department of Chemistry and Bioscience, Aalborg University Copenhagen, A. C. Meyers Vænge 15, 2450, Copenhagen SV, Denmark
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Interaction of Isocitrate Lyase with Proteins Involved in the Energetic Metabolism in Paracoccidioides lutzii. J Fungi (Basel) 2020; 6:jof6040309. [PMID: 33238437 PMCID: PMC7712234 DOI: 10.3390/jof6040309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/06/2020] [Accepted: 11/20/2020] [Indexed: 11/18/2022] Open
Abstract
Background: Systemic mycosis is a cause of death of immunocompromised subjects. The treatment directed to evade fungal pathogens shows severe limitations, such as time of drug exposure and side effects. The paracoccidioidomycosis (PCM) treatment depends on the severity of the infection and may last from months to years. Methods: To analyze the main interactions of Paracoccidioides lutzii isocitrate lyase (ICL) regarding the energetic metabolism through affinity chromatography, we performed blue native PAGE and co-immunoprecipitation to identify ICL interactions. We also performed in silico analysis by homology, docking, hot-spot prediction and contact preference analysis to identify the conformation of ICL complexes. Results: ICL interacted with 18 proteins in mycelium, 19 in mycelium-to-yeast transition, and 70 in yeast cells. Thirty complexes were predicted through docking and contact preference analysis. ICL has seven main regions of interaction with protein partners. Conclusions: ICL seems to interfere with energetic metabolism of P. lutzii, regulating aerobic and anaerobic metabolism as it interacts with proteins from glycolysis, gluconeogenesis, TCA and methylcitrate cycles, mainly through seven hot-spot residues.
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Chroumpi T, Mäkelä MR, de Vries RP. Engineering of primary carbon metabolism in filamentous fungi. Biotechnol Adv 2020; 43:107551. [DOI: 10.1016/j.biotechadv.2020.107551] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 04/28/2020] [Accepted: 04/29/2020] [Indexed: 10/24/2022]
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11
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Upton DJ, McQueen-Mason SJ, Wood AJ. In silico evolution of Aspergillus niger organic acid production suggests strategies for switching acid output. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:27. [PMID: 32123544 PMCID: PMC7038614 DOI: 10.1186/s13068-020-01678-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 02/06/2020] [Indexed: 05/19/2023]
Abstract
BACKGROUND The fungus Aspergillus niger is an important industrial organism for citric acid fermentation; one of the most efficient biotechnological processes. Previously we introduced a dynamic model that captures this process in the industrially relevant batch fermentation setting, providing a more accurate predictive platform to guide targeted engineering. In this article we exploit this dynamic modelling framework, coupled with a robust genetic algorithm for the in silico evolution of A. niger organic acid production, to provide solutions to complex evolutionary goals involving a multiplicity of targets and beyond the reach of simple Boolean gene deletions. We base this work on the latest metabolic models of the parent citric acid producing strain ATCC1015 dedicated to organic acid production with the required exhaustive genomic coverage needed to perform exploratory in silico evolution. RESULTS With the use of our informed evolutionary framework, we demonstrate targeted changes that induce a complete switch of acid output from citric to numerous different commercially valuable target organic acids including succinic acid. We highlight the key changes in flux patterns that occur in each case, suggesting potentially valuable targets for engineering. We also show that optimum acid productivity is achieved through a balance of organic acid and biomass production, requiring finely tuned flux constraints that give a growth rate optimal for productivity. CONCLUSIONS This study shows how a genome-scale metabolic model can be integrated with dynamic modelling and metaheuristic algorithms to provide solutions to complex metabolic engineering goals of industrial importance. This framework for in silico guided engineering, based on the dynamic batch growth relevant to industrial processes, offers considerable potential for future endeavours focused on the engineering of organisms to produce valuable products.
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Affiliation(s)
- Daniel J. Upton
- Department of Biology, University of York, Wentworth Way, York, YO10 5DD UK
| | | | - A. Jamie Wood
- Department of Biology, University of York, Wentworth Way, York, YO10 5DD UK
- Department of Mathematics, University of York, Heslington, York, YO10 5DD UK
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12
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Development of a Cre-loxP-based genetic system in Aspergillus niger ATCC1015 and its application to construction of efficient organic acid-producing cell factories. Appl Microbiol Biotechnol 2019; 103:8105-8114. [DOI: 10.1007/s00253-019-10054-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 07/08/2019] [Accepted: 07/26/2019] [Indexed: 02/06/2023]
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13
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Brandl J, Aguilar-Pontes MV, Schäpe P, Noerregaard A, Arvas M, Ram AFJ, Meyer V, Tsang A, de Vries RP, Andersen MR. A community-driven reconstruction of the Aspergillus niger metabolic network. Fungal Biol Biotechnol 2018; 5:16. [PMID: 30275963 PMCID: PMC6158834 DOI: 10.1186/s40694-018-0060-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 09/17/2018] [Indexed: 11/17/2022] Open
Abstract
Background Aspergillus niger is an important fungus used in industrial applications for enzyme and acid production. To enable rational metabolic engineering of the species, available information can be collected and integrated in a genome-scale model to devise strategies for improving its performance as a host organism. Results In this paper, we update an existing model of A. niger metabolism to include the information collected from 876 publications, thereby expanding the coverage of the model by 940 reactions, 777 metabolites and 454 genes. In the presented consensus genome-scale model of A. niger iJB1325 , we integrated experimental data from publications and patents, as well as our own experiments, into a consistent network. This information has been included in a standardized way, allowing for automated testing and continuous improvements in the future. This repository of experimental data allowed the definition of 471 individual test cases, of which the model complies with 373 of them. We further re-analyzed existing transcriptomics and quantitative physiology data to gain new insights on metabolism. Additionally, the model contains 3482 checks on the model structure, thereby representing the best validated genome-scale model on A. niger developed until now. Strain-specific model versions for strains ATCC 1015 and CBS 513.88 have been created containing all data used for model building, thereby allowing users to adopt the models and check the updated version against the experimental data. The resulting model is compliant with the SBML standard and therefore enables users to easily simulate it using their preferred software solution. Conclusion Experimental data on most organisms are scattered across hundreds of publications and several repositories.To allow for a systems level understanding of metabolism, the data must be integrated in a consistent knowledge network. The A. niger iJB1325 model presented here integrates the available data into a highly curated genome-scale model to facilitate the simulation of flux distributions, as well as the interpretation of other genome-scale data by providing the metabolic context. Electronic supplementary material The online version of this article (10.1186/s40694-018-0060-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Julian Brandl
- 1Technical University of Denmark, Soeltofts Plads, Building 223, 2800 Kongens Lyngby, Denmark
| | - Maria Victoria Aguilar-Pontes
- 2Fungal Physiology, Westerdijk Fungal Biodiversity Institute and Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Paul Schäpe
- 6Berlin University of Technology, Gustav-Meyer-Allee 25, 13355 Berlin, Germany
| | - Anders Noerregaard
- 1Technical University of Denmark, Soeltofts Plads, Building 223, 2800 Kongens Lyngby, Denmark
| | - Mikko Arvas
- 3VTT Technical Research Centre of Finland, Tietotie 2, 02044 Espoo, Finland.,7Present Address: Finnish Red Cross Blood Service, Helsinki, Finland
| | - Arthur F J Ram
- 5Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
| | - Vera Meyer
- 6Berlin University of Technology, Gustav-Meyer-Allee 25, 13355 Berlin, Germany
| | - Adrian Tsang
- 4Concordia University, 7141 Sherbrooke Street West, H4B1R6 Montreal, Québec Canada
| | - Ronald P de Vries
- 2Fungal Physiology, Westerdijk Fungal Biodiversity Institute and Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Mikael R Andersen
- 1Technical University of Denmark, Soeltofts Plads, Building 223, 2800 Kongens Lyngby, Denmark
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Liu J, Li J, Liu Y, Shin HD, Ledesma-Amaro R, Du G, Chen J, Liu L. Synergistic Rewiring of Carbon Metabolism and Redox Metabolism in Cytoplasm and Mitochondria of Aspergillus oryzae for Increased l-Malate Production. ACS Synth Biol 2018; 7:2139-2147. [PMID: 30092627 DOI: 10.1021/acssynbio.8b00130] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
l-Malate is an important platform chemical that has extensive applications in the food, feed, and wine industries. Here, we synergistically engineered the carbon metabolism and redox metabolism in the cytosol and mitochondria of a previously engineered Aspergillus oryzae to further improve the l-malate titer and decrease the byproduct succinate concentration. First, the accumulation of the intermediate pyruvate was eliminated by overexpressing a pyruvate carboxylase from Rhizopus oryzae in the cytosol and mitochondria of A. oryzae, and consequently, the l-malate titer increased 7.5%. Then, malate synthesis via glyoxylate bypass in the mitochondria was enhanced, and citrate synthase in the oxidative TCA cycle was downregulated by RNAi, enhancing the l-malate titer by 10.7%. Next, the exchange of byproducts (succinate and fumarate) between the cytosol and mitochondria was regulated by the expression of a dicarboxylate carrier Sfc1p from Saccharomyces cerevisiae in the mitochondria, which increased l-malate titer 3.5% and decreased succinate concentration 36.8%. Finally, an NADH oxidase from Lactococcus lactis was overexpressed to decrease the NADH/NAD+ ratio, and the engineered A. oryzae strain produced 117.2 g/L l-malate and 3.8 g/L succinate, with an l-malate yield of 0.9 g/g corn starch and a productivity of 1.17 g/L/h. Our results showed that synergistic engineering of the carbon and redox metabolisms in the cytosol and mitochondria of A. oryzae effectively increased the l-malate titer, while simultaneously decreasing the concentration of the byproduct succinate. The strategies used in our work may be useful for the metabolic engineering of fungi to produce other industrially important chemicals.
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Affiliation(s)
- Jingjing Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Jianghua Li
- Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Yanfeng Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Hyun-dong Shin
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | | | - Guocheng Du
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Jian Chen
- Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Long Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
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15
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Beattie SR, Mark KMK, Thammahong A, Ries LNA, Dhingra S, Caffrey-Carr AK, Cheng C, Black CC, Bowyer P, Bromley MJ, Obar JJ, Goldman GH, Cramer RA. Filamentous fungal carbon catabolite repression supports metabolic plasticity and stress responses essential for disease progression. PLoS Pathog 2017; 13:e1006340. [PMID: 28423062 PMCID: PMC5411099 DOI: 10.1371/journal.ppat.1006340] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 05/01/2017] [Accepted: 04/08/2017] [Indexed: 12/13/2022] Open
Abstract
Aspergillus fumigatus is responsible for a disproportionate number of invasive mycosis cases relative to other common filamentous fungi. While many fungal factors critical for infection establishment are known, genes essential for disease persistence and progression are ill defined. We propose that fungal factors that promote navigation of the rapidly changing nutrient and structural landscape characteristic of disease progression represent untapped clinically relevant therapeutic targets. To this end, we find that A. fumigatus requires a carbon catabolite repression (CCR) mediated genetic network to support in vivo fungal fitness and disease progression. While CCR as mediated by the transcriptional repressor CreA is not required for pulmonary infection establishment, loss of CCR inhibits fungal metabolic plasticity and the ability to thrive in the dynamic infection microenvironment. Our results suggest a model whereby CCR in an environmental filamentous fungus is dispensable for initiation of pulmonary infection but essential for infection maintenance and disease progression. Conceptually, we argue these data provide a foundation for additional studies on fungal factors required to support fungal fitness and disease progression and term such genes and factors, DPFs (disease progression factors).
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Affiliation(s)
- Sarah R. Beattie
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Kenneth M. K. Mark
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Arsa Thammahong
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | | | - Sourabh Dhingra
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Alayna K. Caffrey-Carr
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, United States of America
| | - Chao Cheng
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
- Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, United States of America
- Institute for Quantitative Biomedical Sciences, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, United States of America
| | - Candice C. Black
- Department of Pathology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, United States of America
| | - Paul Bowyer
- Manchester Fungal Infection Group, School of Biological Sciences, University of Manchester, Manchester, United Kingdom
| | - Michael J. Bromley
- Manchester Fungal Infection Group, School of Biological Sciences, University of Manchester, Manchester, United Kingdom
| | - Joshua J. Obar
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Brazil
| | - Robert A. Cramer
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
- * E-mail:
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16
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Biotechnological route for sustainable succinate production utilizing oil palm frond and kenaf as potential carbon sources. Appl Microbiol Biotechnol 2017; 101:3055-3075. [PMID: 28280869 DOI: 10.1007/s00253-017-8210-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 02/20/2017] [Accepted: 02/21/2017] [Indexed: 10/20/2022]
Abstract
Due to the world's dwindling energy supplies, greater thrust has been placed on the utilization of renewable resources for global succinate production. Exploration of such biotechnological route could be seen as an act of counterbalance to the continued fossil fuel dominance. Malaysia being a tropical country stands out among many other nations for its plenty of resources in the form of lignocellulosic biomass. To date, oil palm frond (OPF) contributes to the largest fraction of agricultural residues in Malaysia, while kenaf, a newly introduced fiber crop with relatively high growth rate, holds great potential for developing sustainable succinate production, apart from OPF. Utilization of non-food, inexhaustible, and low-cost derived biomass in the form of OPF and kenaf for bio-based succinate production remains largely untapped. Owing to the richness of carbohydrates in OPF and kenaf, bio-succinate commercialization using these sources appears as an attractive proposition for future sustainable developments. The aim of this paper was to review some research efforts in developing a biorefinery system based on OPF and kenaf as processing inputs. It presents the importance of the current progress in bio-succinate commercialization, in addition to describing the potential use of different succinate production hosts and various pretreatments-saccharifications under development for OPF and kenaf. Evaluations on the feasibility of OPF and kenaf as fermentation substrates are also discussed.
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17
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P gas, a Low-pH-Induced Promoter, as a Tool for Dynamic Control of Gene Expression for Metabolic Engineering of Aspergillus niger. Appl Environ Microbiol 2017; 83:AEM.03222-16. [PMID: 28087530 DOI: 10.1128/aem.03222-16] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 12/30/2016] [Indexed: 11/20/2022] Open
Abstract
The dynamic control of gene expression is important for adjusting fluxes in order to obtain desired products and achieve appropriate cell growth, particularly when the synthesis of a desired product drains metabolites required for cell growth. For dynamic gene expression, a promoter responsive to a particular environmental stressor is vital. Here, we report a low-pH-inducible promoter, Pgas, which promotes minimal gene expression at pH values above 5.0 but functions efficiently at low pHs, such as pH 2.0. First, we performed a transcriptional analysis of Aspergillus niger, an excellent platform for the production of organic acids, and we found that the promoter Pgas may act efficiently at low pH. Then, a gene for synthetic green fluorescent protein (sGFP) was successfully expressed by Pgas at pH 2.0, verifying the results of the transcriptional analysis. Next, Pgas was used to express the cis-aconitate decarboxylase (cad) gene of Aspergillus terreus in A. niger, allowing the production of itaconic acid at a titer of 4.92 g/liter. Finally, we found that Pgas strength was independent of acid type and acid ion concentration, showing dependence on pH only.IMPORTANCE The promoter Pgas can be used for the dynamic control of gene expression in A. niger for metabolic engineering to produce organic acids. This promoter may also be a candidate tool for genetic engineering.
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18
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Yang L, Lübeck M, Lübeck PS. Aspergillus as a versatile cell factory for organic acid production. FUNGAL BIOL REV 2017. [DOI: 10.1016/j.fbr.2016.11.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Identification of cypermethrin induced protein changes in green algae by iTRAQ quantitative proteomics. J Proteomics 2016; 139:67-76. [DOI: 10.1016/j.jprot.2016.03.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 03/01/2016] [Accepted: 03/02/2016] [Indexed: 12/26/2022]
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20
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Kamzolova SV, Allayarov RK, Lunina JN, Morgunov IG. The effect of oxalic and itaconic acids on threo-Ds-isocitric acid production from rapeseed oil by Yarrowia lipolytica. BIORESOURCE TECHNOLOGY 2016; 206:128-133. [PMID: 26851896 DOI: 10.1016/j.biortech.2016.01.092] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 01/24/2016] [Accepted: 01/25/2016] [Indexed: 05/07/2023]
Abstract
The effect of oxalic and itaconic acids, the inhibitors of the isocitrate lyase, on the production of isocitric acid by the wild strain Yarrowia lipolytica VKM Y-2373 grown in the medium containing rapeseed oil was studied. In the presence of oxalic and itaconic acids, strain Y. lipolytica accumulated in the medium isocitric acid (70.0 and 82.7 g/L, respectively) and citric acid (23.0 and 18.4 g/L, respectively). In control experiment, when the inhibitors were not added to the medium, the strain accumulated isocitric and citric acids at concentrations of 62.0 and 28.0 g/L, respectively. Thus, the use of the oxalic and itaconic acids as additives to the medium is a simple and convenient method of isocitric acid production with a minimum content of citric acid.
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Affiliation(s)
- Svetlana V Kamzolova
- G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino 142290, Russia.
| | - Ramil K Allayarov
- G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino 142290, Russia
| | - Julia N Lunina
- G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino 142290, Russia
| | - Igor G Morgunov
- G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino 142290, Russia
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21
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Expression of Lactate Dehydrogenase in Aspergillus niger for L-Lactic Acid Production. PLoS One 2015; 10:e0145459. [PMID: 26683313 PMCID: PMC4684279 DOI: 10.1371/journal.pone.0145459] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 12/03/2015] [Indexed: 11/19/2022] Open
Abstract
Different engineered organisms have been used to produce L-lactate. Poor yields of lactate at low pH and expensive downstream processing remain as bottlenecks. Aspergillus niger is a prolific citrate producer and a remarkably acid tolerant fungus. Neither a functional lactate dehydrogenase (LDH) from nor lactate production by A. niger is reported. Its genome was also investigated for the presence of a functional ldh. The endogenous A. niger citrate synthase promoter relevant to A. niger acidogenic metabolism was employed to drive constitutive expression of mouse lactate dehydrogenase (mldhA). An appraisal of different branches of the A. niger pyruvate node guided the choice of mldhA for heterologous expression. A high copy number transformant C12 strain, displaying highest LDH specific activity, was analyzed under different growth conditions. The C12 strain produced 7.7 g/l of extracellular L-lactate from 60 g/l of glucose, in non-neutralizing minimal media. Significantly, lactate and citrate accumulated under two different growth conditions. Already an established acidogenic platform, A. niger now promises to be a valuable host for lactate production.
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22
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Enhanced succinic acid production in Aspergillus saccharolyticus by heterologous expression of fumarate reductase from Trypanosoma brucei. Appl Microbiol Biotechnol 2015; 100:1799-1809. [PMID: 26521243 DOI: 10.1007/s00253-015-7086-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 10/04/2015] [Accepted: 10/13/2015] [Indexed: 10/22/2022]
Abstract
Aspergillus saccharolyticus exhibits great potential as a cell factory for industrial production of dicarboxylic acids. In the analysis of the organic acid profile, A. saccharolyticus was cultivated in an acid production medium using two different pH conditions. The specific activities of the enzymes, pyruvate carboxylase (PYC), malate dehydrogenase (MDH), and fumarase (FUM), involved in the reductive tricarboxylic acid (rTCA) branch, were examined and compared in cells harvested from the acid production medium and a complete medium. The results showed that ambient pH had a significant impact on the pattern and the amount of organic acids produced by A. saccharolyticus. The wild-type strain produced higher amount of malic acid and succinic acid in the pH buffered condition (pH 6.5) compared with the pH non-buffered condition. The enzyme assays showed that the rTCA branch was active in the acid production medium as well as the complete medium, but the measured enzyme activities were different depending on the media. Furthermore, a soluble NADH-dependent fumarate reductase gene (frd) from Trypanosoma brucei was inserted and expressed in A. saccharolyticus. The expression of the frd gene led to an enhanced production of succinic acid in frd transformants compared with the wild-type in both pH buffered and pH non-buffered conditions with highest amount produced in the pH buffered condition (16.2 ± 0.5 g/L). This study demonstrates the feasibility of increasing succinic acid production through the cytosolic reductive pathway by genetic engineering in A. saccharolyticus.
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Physiological characterization of the high malic acid-producing Aspergillus oryzae strain 2103a-68. Appl Microbiol Biotechnol 2014; 98:3517-27. [DOI: 10.1007/s00253-013-5465-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 12/09/2013] [Accepted: 12/10/2013] [Indexed: 01/11/2023]
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24
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Fermentative succinate production: an emerging technology to replace the traditional petrochemical processes. BIOMED RESEARCH INTERNATIONAL 2013; 2013:723412. [PMID: 24396827 PMCID: PMC3874355 DOI: 10.1155/2013/723412] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Revised: 10/13/2013] [Accepted: 11/01/2013] [Indexed: 11/17/2022]
Abstract
Succinate is a valuable platform chemical for multiple applications. Confronted with the exhaustion of fossil energy resources, fermentative succinate production from renewable biomass to replace the traditional petrochemical process is receiving an increasing amount of attention. During the past few years, the succinate-producing process using microbial fermentation has been made commercially available by the joint efforts of researchers in different fields. In this review, recent attempts and experiences devoted to reduce the production cost of biobased succinate are summarized, including strain improvement, fermentation engineering, and downstream processing. The key limitations and challenges faced in current microbial production systems are also proposed.
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Alagesan S, Gaudana SB, Sinha A, Wangikar PP. Metabolic flux analysis of Cyanothece sp. ATCC 51142 under mixotrophic conditions. PHOTOSYNTHESIS RESEARCH 2013; 118:191-198. [PMID: 23954952 DOI: 10.1007/s11120-013-9911-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 08/06/2013] [Indexed: 06/02/2023]
Abstract
Cyanobacteria are a group of photosynthetic prokaryotes capable of utilizing solar energy to fix atmospheric carbon dioxide to biomass. Despite several "proof of principle" studies, low product yield is an impediment in commercialization of cyanobacteria-derived biofuels. Estimation of intracellular reaction rates by (13)C metabolic flux analysis ((13)C-MFA) would be a step toward enhancing biofuel yield via metabolic engineering. We report (13)C-MFA for Cyanothece sp. ATCC 51142, a unicellular nitrogen-fixing cyanobacterium, known for enhanced hydrogen yield under mixotrophic conditions. Rates of reactions in the central carbon metabolism under nitrogen-fixing and -non-fixing conditions were estimated by monitoring the competitive incorporation of (12)C and (13)C from unlabeled CO2 and uniformly labeled glycerol, respectively, into terminal metabolites such as amino acids. The observed labeling patterns suggest mixotrophic growth under both the conditions, with a larger fraction of unlabeled carbon in nitrate-sufficient cultures asserting a greater contribution of carbon fixation by photosynthesis and an anaplerotic pathway. Indeed, flux analysis complements the higher growth observed under nitrate-sufficient conditions. On the other hand, the flux through the oxidative pentose phosphate pathway and tricarboxylic acid cycle was greater in nitrate-deficient conditions, possibly to supply the precursors and reducing equivalents needed for nitrogen fixation. In addition, an enhanced flux through fructose-6-phosphate phosphoketolase possibly suggests the organism's preferred mode under nitrogen-fixing conditions. The (13)C-MFA results complement the reported predictions by flux balance analysis and provide quantitative insight into the organism's distinct metabolic features under nitrogen-fixing and -non-fixing conditions.
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Affiliation(s)
- Swathi Alagesan
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
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Pey J, Rubio A, Theodoropoulos C, Cascante M, Planes FJ. Integrating tracer-based metabolomics data and metabolic fluxes in a linear fashion via Elementary Carbon Modes. Metab Eng 2012; 14:344-53. [DOI: 10.1016/j.ymben.2012.03.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 03/01/2012] [Accepted: 03/26/2012] [Indexed: 01/10/2023]
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Integration of in vivo and in silico metabolic fluxes for improvement of recombinant protein production. Metab Eng 2011; 14:47-58. [PMID: 22115737 DOI: 10.1016/j.ymben.2011.11.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 10/12/2011] [Accepted: 11/02/2011] [Indexed: 01/20/2023]
Abstract
The filamentous fungus Aspergillus niger is an efficient host for the recombinant production of the glycosylated enzyme fructofuranosidase, a biocatalyst of commercial interest for the synthesis of pre-biotic sugars. In batch culture on a minimal glucose medium, the recombinant strain A. niger SKAn1015, expressing the fructofuranosidase encoding suc1 gene secreted 45U/mL of the target enzyme, whereas the parent wild type SKANip8 did not exhibit production. The production of the recombinant enzyme induced a significant change of in vivo fluxes in central carbon metabolism, as assessed by (13)C metabolic flux ratio analysis. Most notably, the flux redistribution enabled an elevated supply of NADPH via activation of the cytosolic pentose phosphate pathway (PPP) and mitochondrial malic enzyme, whereas the flux through energy generating TCA cycle was reduced. In addition, the overall possible flux space of fructofuranosidase producing A. niger was investigated in silico by elementary flux mode analysis. This provided theoretical flux distributions for multiple scenarios with differing production capacities. Subsequently, the measured flux changes linked to improved production performance were projected into the in silico flux space. This provided a quantitative evaluation of the achieved optimization and a priority ranked target list for further strain engineering. Interestingly, the metabolism was shifted largely towards the optimum flux pattern by sole expression of the recombinant enzyme, which seems an inherent attractive property of A. niger. Selected fluxes, however, changed contrary to the predicted optimum and thus revealed novel targets-including reactions linked to NADPH metabolism and gluconate formation.
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Martínez I, Bennett GN, San KY. Metabolic impact of the level of aeration during cell growth on anaerobic succinate production by an engineered Escherichia coli strain. Metab Eng 2010; 12:499-509. [PMID: 20883813 DOI: 10.1016/j.ymben.2010.09.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2010] [Revised: 09/07/2010] [Accepted: 09/21/2010] [Indexed: 11/16/2022]
Abstract
The metabolic impact of two different aeration conditions during the growth phase on anaerobic succinate production by the high succinate producer Escherichia coli SBS550MG (pHL413) was investigated. Gene expression profiles, metabolites concentrations and metabolic fluxes were analyzed. Different oxygen levels are known to induce or repress transcription, synthesis of different enzymes, or both, affecting cell metabolism and thus product yield and productivity. The succinate yield was 1.55 and 1.25 mol succinate/mol glucose, and the productivity was 1.3 and 0.9 g L(-1)h(-1)) for the low aeration experiment and high aeration experiment, respectively. Changes in the level of aeration during the cells growth phase significantly modified gene expression profiles and metabolic fluxes in this system. Pyruvate was accumulated during the anaerobic phase in the high aeration experiment, which could be explained by a lower pflAB expression during the transition time and a lower flux towards acetyl-CoA during the anaerobic phase compared to the low aeration case. The higher PflAB flux and the higher expression of genes related to the glyoxylate shunt (aceA, aceB, acnA, acnB) during the transition time, anaerobic phase, or both, improved succinate yield in the low aeration case, allowing the system to attain the maximum theoretical succinate yield for E. coli SBS550MG (pHL413).
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Affiliation(s)
- Irene Martínez
- Department of Bioengineering, Rice University, Houston, TX, USA
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Liu XY, Chi Z, Liu GL, Wang F, Madzak C, Chi ZM. Inulin hydrolysis and citric acid production from inulin using the surface-engineered Yarrowia lipolytica displaying inulinase. Metab Eng 2010; 12:469-76. [DOI: 10.1016/j.ymben.2010.04.004] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Revised: 04/14/2010] [Accepted: 04/27/2010] [Indexed: 10/19/2022]
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Metabolic flux analysis in eukaryotes. Curr Opin Biotechnol 2010; 21:63-9. [PMID: 20163950 DOI: 10.1016/j.copbio.2010.01.011] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2009] [Revised: 01/15/2010] [Accepted: 01/20/2010] [Indexed: 02/05/2023]
Abstract
Metabolic flux analysis (MFA) represents a powerful tool for systems biology research on eukaryotic cells. This review describes recent advances, the challenges as well as applications of metabolic flux analysis comprising fungi, mammalian cells and plants. While MFA is widely established and applied in microorganisms, it remains still a challenge to adapt these methods to eukaryotic cell systems having a higher complexity particularly concerning compartmentation or media composition. In fungi MFA was used in the past few years to analyze a variety of conditions and factors and their effects on cellular metabolism. In mammalian cells MFA was applied mainly in cell culture technology and in medical and toxicological research. (13)C metabolic studies on native whole plants are additionally challenging by the fact that CO(2) is usually the only carbon source.
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