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Sun X, Gao F, Fan C, Yang S, Zhao T, Tu T, Luo H, Yao B, Huang H, Su X. Sub-genomic RNAi-assisted strain evolution of filamentous fungi for enhanced protein production. Appl Environ Microbiol 2024:e0208223. [PMID: 38899886 DOI: 10.1128/aem.02082-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Accepted: 05/27/2024] [Indexed: 06/21/2024] Open
Abstract
Genetic engineering at the genomic scale provides a rapid means to evolve microbes for desirable traits. However, in many filamentous fungi, such trials are daunted by low transformation efficiency. Differentially expressed genes under certain conditions may contain important regulatory factors. Accordingly, although manipulating these subsets of genes only can largely reduce the time and labor, engineering at such a sub-genomic level may also be able to improve the microbial performance. Herein, first using the industrially important cellulase-producing filamentous fungus Trichoderma reesei as a model organism, we constructed suppression subtractive hybridization (SSH) libraries enriched with differentially expressed genes under cellulase induction (MM-Avicel) and cellulase repression conditions (MM-Glucose). The libraries, in combination with RNA interference, enabled sub-genomic engineering of T. reesei for enhanced cellulase production. The ability of T. reesei to produce endoglucanase was improved by 2.8~3.3-fold. In addition, novel regulatory genes (tre49304, tre120391, and tre123541) were identified to affect cellulase expression in T. reesei. Iterative manipulation using the same strategy further increased the yield of endoglucanase activity to 75.6 U/mL, which was seven times as high as that of the wild type (10.8 U/mL). Moreover, using Humicola insolens as an example, such a sub-genomic RNAi-assisted strain evolution proved to be also useful in other industrially important filamentous fungi. H. insolens is a filamentous fungus commonly used to produce catalase, albeit with similarly low transformation efficiency and scarce knowledge underlying the regulation of catalase expression. By combining SSH and RNAi, a strain of H. insolens producing 28,500 ± 288 U/mL of catalase was obtained, which was 1.9 times as high as that of the parent strain.IMPORTANCEGenetic engineering at the genomic scale provides an unparalleled advantage in microbial strain improvement, which has previously been limited only to the organisms with high transformation efficiency such as Saccharomyces cerevisiae and Escherichia coli. Herein, using the filamentous fungus Trichoderma reesei as a model organism, we demonstrated that the advantage of suppression subtractive hybridization (SSH) to enrich differentially expressed genes and the convenience of RNA interference to manipulate a multitude of genes could be combined to overcome the inadequate transformation efficiency. With this sub-genomic evolution strategy, T. reesei could be iteratively engineered for higher cellulase production. Intriguingly, Humicola insolens, a fungus with even little knowledge in gene expression regulation, was also improved for catalase production. The same strategy may also be expanded to engineering other microorganisms for enhanced production of proteins, organic acids, and secondary metabolites.
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Affiliation(s)
- Xianhua Sun
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Fei Gao
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Chao Fan
- Key Laboratory of Birth Regulation and Control Technology of National Health Commission of China, Shandong Provincial Maternal and Child Health Care Hospital Affiliated to Qingdao University, Jinan, China
| | - Shuyan Yang
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Tong Zhao
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Tao Tu
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Huiying Luo
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Bin Yao
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Huoqing Huang
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiaoyun Su
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
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Zhang R, Chen Y, Wang W, Chen J, Liu D, Zhang L, Xiang Q, Zhao K, Ma M, Yu X, Chen Q, Penttinen P, Gu Y. Combined transcriptomic and metabolomic analysis revealed that pH changes affected the expression of carbohydrate and ribosome biogenesis-related genes in Aspergillus niger SICU-33. Front Microbiol 2024; 15:1389268. [PMID: 38962137 PMCID: PMC11220263 DOI: 10.3389/fmicb.2024.1389268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 06/03/2024] [Indexed: 07/05/2024] Open
Abstract
The process of carbohydrate metabolism and genetic information transfer is an important part of the study on the effects of the external environment on microbial growth and development. As one of the most significant environmental parameters, pH has an important effect on mycelial growth. In this study, the effects of environmental pH on the growth and nutrient composition of Aspergillus niger (A. niger) filaments were determined. The pH values of the medium were 5, 7, and 9, respectively, and the molecular mechanism was further investigated by transcriptomics and metabolomics methods. The results showed that pH 5 and 9 significantly inhibited filament growth and polysaccharide accumulation of A. niger. Further, the mycelium biomass of A. niger and the crude polysaccharide content was higher when the medium's pH was 7. The DEGs related to ribosome biogenesis were the most abundant, and the downregulated expression of genes encoding XRN1, RRM, and RIO1 affected protein translation, modification, and carbohydrate metabolism in fungi. The dynamic changes of pargyline and choline were in response to the oxidative metabolism of A. niger SICU-33. The ribophorin_I enzymes and DL-lactate may be important substances related to pH changes during carbohydrate metabolism of A.niger SICU-33. The results of this study provide useful transcriptomic and metabolomic information for further analyzing the bioinformatic characteristics of A. niger and improving the application in ecological agricultural fermentation.
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Affiliation(s)
- Runji Zhang
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Yulan Chen
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Wenxian Wang
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Juan Chen
- Liangshan Tobacco Corporation of Sichuan Province, Xichang, China
| | - Dongyang Liu
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
- Liangshan Tobacco Corporation of Sichuan Province, Xichang, China
| | - Lingzi Zhang
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Quanju Xiang
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Ke Zhao
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Menggen Ma
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Xiumei Yu
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Qiang Chen
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Petri Penttinen
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Yunfu Gu
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
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Liu J, Wang D, Wang H, Yang N, Hou J, Lv X, Gong L. Low frequency magnetic field assisted production of acidic protease by Aspergillus niger. Arch Microbiol 2024; 206:273. [PMID: 38772954 DOI: 10.1007/s00203-024-04004-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Accepted: 05/14/2024] [Indexed: 05/23/2024]
Abstract
Acid protease is widely used in industries such as food processing and feed additives. In the study, low frequency magnetic field (LF-MF) as an aid enhances acid protease production by Aspergillus niger (A. niger). The study assessed mycelial biomass, the enzymic activity of the acidic protease and underlying mechanism. At low intensities, alternating magnetic field (AMF) is more effective than static magnetic fields (SMF). Under optimal magnetic field conditions, acid protease activity and biomass increased by 91.44% and 16.31%, as compared with the control, respectively. Maximum 19.87% increase in enzyme activity after magnetic field treatment of crude enzyme solution in control group. Transcriptomics analyses showed that low frequency alternating magnetic field (LF-AMF) treatment significantly upregulated genes related to hydrolases and cell growth. Our results showed that low-frequency magnetic fields can enhance the acid protease production ability of A. niger, and the effect of AMF is better at low intensities. The results revealed that the effect of magnetic field on the metabolic mechanism of A. niger and provided a reference for magnetic field-assisted fermentation of A. niger.
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Affiliation(s)
- Jinlong Liu
- College of Food and Biology, Hebei University of Science and Technology, ShiJiaZhuang, 050018, China.
- Hebei Fermentation Technology Innovation Center, Hebei University of Science and Technology, ShiJiaZhuang, 050018, China.
| | - Dongxu Wang
- College of Food and Biology, Hebei University of Science and Technology, ShiJiaZhuang, 050018, China
| | - Hong Wang
- College of Food and Biology, Hebei University of Science and Technology, ShiJiaZhuang, 050018, China
| | - Na Yang
- School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Jiayang Hou
- College of Food and Biology, Hebei University of Science and Technology, ShiJiaZhuang, 050018, China
| | - Xuemeng Lv
- College of Food and Biology, Hebei University of Science and Technology, ShiJiaZhuang, 050018, China
| | - Luqian Gong
- College of Food and Biology, Hebei University of Science and Technology, ShiJiaZhuang, 050018, China
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Xu J, Cheng S, Zhang R, Cai F, Zhu Z, Cao J, Wang J, Yu Q. Study on the mechanism of sodium ion inhibiting citric acid fermentation in Aspergillus niger. BIORESOURCE TECHNOLOGY 2024; 394:130245. [PMID: 38145764 DOI: 10.1016/j.biortech.2023.130245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/20/2023] [Accepted: 12/20/2023] [Indexed: 12/27/2023]
Abstract
Excessive sodium significantly inhibits citric acid fermentation by Aspergillus niger during the recycling of citric acid wastewater. This study aimed to elucidate the inhibition mechanism at the interface of physiology and transcriptomics. The results showed that excessive sodium caused a 22.3 % increase in oxalic acid secretion and a 147.6 % increase in H+-ATPase activity at the 4 h fermentation compared to the control. Meanwhile, a 13.1 % reduction in energy charge level and a 15.2 % decline in NADH content were found, which implied the effects on carbon metabolism and redox balance. In addition, transcriptomic analysis revealed that excessive sodium altered the gene expression profiles related to ATPase, hydrolase, and oxidoreductase, as well as pathways like glyoxylate metabolism, and transmembrane transport. These findings gained insights into the metabolic regulation of A. niger response to environmental stress and provided theoretical guidance for the construction of sodium-tolerant A. niger for industrial application.
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Affiliation(s)
- Jian Xu
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, School of Food and Biological Engineering, Hubei University of Technology, 28 Nanli Road, Wuhan 430068, China
| | - Sulian Cheng
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, School of Food and Biological Engineering, Hubei University of Technology, 28 Nanli Road, Wuhan 430068, China
| | - Ruijing Zhang
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, School of Food and Biological Engineering, Hubei University of Technology, 28 Nanli Road, Wuhan 430068, China
| | - Fengjiao Cai
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, School of Food and Biological Engineering, Hubei University of Technology, 28 Nanli Road, Wuhan 430068, China
| | - Zhengjun Zhu
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, School of Food and Biological Engineering, Hubei University of Technology, 28 Nanli Road, Wuhan 430068, China
| | - Jinghua Cao
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, School of Food and Biological Engineering, Hubei University of Technology, 28 Nanli Road, Wuhan 430068, China
| | - Jiangbo Wang
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, School of Food and Biological Engineering, Hubei University of Technology, 28 Nanli Road, Wuhan 430068, China
| | - Qi Yu
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, School of Food and Biological Engineering, Hubei University of Technology, 28 Nanli Road, Wuhan 430068, China.
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Fermentation of Agri-Food Waste: A Promising Route for the Production of Aroma Compounds. Foods 2021; 10:foods10040707. [PMID: 33810435 PMCID: PMC8066995 DOI: 10.3390/foods10040707] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/21/2021] [Accepted: 03/22/2021] [Indexed: 12/13/2022] Open
Abstract
Food waste and byproducts are generated along the entire food processing and storage chain. The large amount of waste deriving from the whole process represents not only a great economic loss but also an important ethical and environmental issue in terms of failure to recycle potentially reusable materials. New, clear strategies are needed to limit the amount of waste produced and, at the same time, promote its enhancement for further conversion and application to different industrial fields. This review gives an overview of the biological approaches used so far to exploit agri-food wastes and byproducts. The application of solid-state fermentation by different microorganisms (fungi, yeasts, bacteria) to produce several value-added products was analyzed, focusing on the exploitation of lactic acid bacteria as workhorses for the production of flavoring compounds.
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Zhang J, Zhang X, Mao Y, Jin B, Guo Y, Wang Z, Chen T. Substrate profiling and tolerance testing of Halomonas TD01 suggest its potential application in sustainable manufacturing of chemicals. J Biotechnol 2020; 316:1-5. [PMID: 32311394 DOI: 10.1016/j.jbiotec.2020.04.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/10/2020] [Accepted: 04/13/2020] [Indexed: 01/19/2023]
Abstract
Halomonas TD01, which can grow under non-sterile and continuous processes at high pH and high salt concentrations, is a robust platform for PHA production from glucose. For extending other low-cost sustainable substrates and increasing the potential application in other value-added products, a better understanding of substrates utilization and chemicals tolerance is necessary. In this study, the substrate profiling of TD01 was analyzed via Biolog. Phenotype microarray results demonstrated that TD01 has a wide-ranging substrate spectrum and can utilize 140 of the 190 test compounds. Some cheap, abundant carbon sources, such as sodium acetate, glycerol, ethanol and lactate can well support the growth of TD01 in shake-flask, and are therefore suggested to be its alternative low-cost substrates for chemicals production in future. Furthermore, the tolerance of TD01 to various chemicals was tested. The results showed that the tolerability of TD01 to high concentrations of organic acid salts is prominent. When adding 75 g/L sodium acetate, 100 g/L succinic acid and 100 g/L itaconic acid in the medium, the growth rate reduced 56.14%, 52.63% and 47.37%, respectively. All these results highlight TD01 as a promising, next generation industrial workhorse in chemicals biomanufacturing from cheap organic acid salts.
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Affiliation(s)
- Jing Zhang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering of Ministry of Education, SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Xin Zhang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering of Ministry of Education, SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Yufeng Mao
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Biao Jin
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering of Ministry of Education, SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Yanmei Guo
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Zhiwen Wang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering of Ministry of Education, SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Tao Chen
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering of Ministry of Education, SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
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Xie H, Ma Q, Wei D, Wang F. Metabolic engineering of an industrial Aspergillus niger strain for itaconic acid production. 3 Biotech 2020; 10:113. [PMID: 32117674 DOI: 10.1007/s13205-020-2080-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 01/20/2020] [Indexed: 02/04/2023] Open
Abstract
Itaconic acid is a value-added organic acid that is widely applied in industrial production. It can be converted from citric acid by some microorganisms including Aspergillus terreus and Aspergillus niger. Because of high citric acid production (more than 200 g/L), A. niger strains may be developed into powerful itaconic acid-producing microbial cell factories. In this study, industrial citric acid-producing strain A. niger YX-1217, capable of producing 180.0-200.0 g/L, was modified to produce itaconic acid by metabolic engineering. A key gene cadA encoding aconitase was expressed in A. niger YX-1217 under the control of three different promoters. Analyses showed that the PglaA promoter resulted in higher levels of gene expression than the PpkiA and PgpdA promoters. Moreover, the synthesis pathway of itaconic acid was extended by introducing the acoA gene, and the cadA gene, encoding aconitate decarboxylase, into A. niger YX-1217 under the function of the two rigid short-peptide linkers L1 or L2. The resulting recombinant strains L-1 and L-2 were induced to produce itaconic acid in fed-batch fermentations under three-stage control of agitation speed. After fermentation for 104 h, itaconic acid concentrations in the recombinant strain L-2 culture reached 7.2 g/L, which represented a 71.4% increase in itaconic acid concentration compared with strain Z-17 that only expresses cadA. Therefore, co-expression of acoA and cadA resulted in an extension of the citric acid metabolic pathway to the itaconic acid metabolic pathway, thereby increasing the production of itaconic acid by A. niger.
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Affiliation(s)
- Hui Xie
- 1State Key Lab of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237 China
- 2Life Science College, Henan Agricultural University, Zhengzhou, 450002 China
| | - Qinyuan Ma
- Weifang Ensign Industry Co., Ltd, Weifang, 262499 China
| | - Dongzhi Wei
- 1State Key Lab of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237 China
| | - Fengqing Wang
- 1State Key Lab of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237 China
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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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Clinostat Rotation Affects Metabolite Transportation and Increases Organic Acid Production by Aspergillus carbonarius, as Revealed by Differential Metabolomic Analysis. Appl Environ Microbiol 2019; 85:AEM.01023-19. [PMID: 31300399 DOI: 10.1128/aem.01023-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 06/27/2019] [Indexed: 02/06/2023] Open
Abstract
Contamination by fungi may pose a threat to the long-term operation of the International Space Station because fungi produce organic acids that corrode equipment and mycotoxins that harm human health. Microgravity is an unavoidable and special condition in the space station. However, the influence of microgravity on fungal metabolism has not been well studied. Clinostat rotation is widely used to simulate the microgravity condition in studies carried out on Earth. Here, we used metabolomics differential analysis to study the influence of clinostat rotation on the accumulation of organic acids and related biosynthetic pathways in ochratoxin A (OTA)-producing Aspergillus carbonarius As a result, clinostat rotation did not affect fungal cell growth or colony appearance but significantly increased the accumulation of organic acids, particularly isocitric acid, citric acid, and oxalic acid, and OTA both inside cells and in the medium, as well as resulted in a much higher level of accumulation of some products inside than outside cells, indicating that the transport of these metabolites from the cell to the medium was inhibited. This finding corresponded to the change in the fatty acid composition of cell membranes and the reduced thickness of the cell walls and cell membranes. Amino acid and energy metabolic pathways, particularly the tricarboxylic acid cycle, were influenced the most during clinostat rotation compared to the effects of normal gravity on these pathways.IMPORTANCE Fungi are ubiquitous in nature and have the ability to corrode various materials by producing metabolites. Research on how the space station environment, especially microgravity, affects fungal metabolism is helpful to understand the role of fungi in the space station. This work provides insights into the mechanisms involved in the metabolism of the corrosive fungus Aspergillus carbonarius under simulated microgravity conditions. Our findings have significance not only for preventing material corrosion but also for ensuring food safety, especially in the space environment.
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Metabolic profiling and flux distributions reveal a key role of acetyl-CoA in sophorolipid synthesis by Candida bombicola. Biochem Eng J 2019. [DOI: 10.1016/j.bej.2019.02.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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