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Fekete E, Bíró V, Márton A, Bakondi-Kovács I, Sándor E, Kovács B, Geoffrion N, Tsang A, Kubicek CP, Karaffa L. Transcriptomics identify the triggering of citrate export as the key event caused by manganese deficiency in Aspergillus niger. Microbiol Spectr 2024:e0190624. [PMID: 39377610 DOI: 10.1128/spectrum.01906-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2024] [Accepted: 09/04/2024] [Indexed: 10/09/2024] Open
Abstract
For over a century, the filamentous Ascomycete fungus Aspergillus niger has played a pivotal role in the industrial production of citric acid. A critical fermentation parameter that sustains high-yield citric acid accumulation is the suboptimal concentration of manganese(II) ions in the culture broth at the early stages of the process. However, the requirement for this deficiency has not been investigated on a functional genomics level. In this study, we compared the transcriptome of the citric acid hyper-producer A. niger NRRL2270 strain grown under citric acid-producing conditions in 6-L scale bioreactors at Mn2+ ion-deficient (5 ppb) and Mn2+ ion-sufficient (100 ppb) conditions at three early time points of cultivation. Of the 11,846 genes in the genome, 963 genes (8.1% of the total) were identified as significantly differentially expressed under these conditions. Disproportionately high number of differentially regulated genes encode predicted extracellular and membrane proteins. The most abundant gene group that was upregulated in Mn2+ ion deficiency condition encodes enzymes acting on polysaccharides. In contrast, six clusters of genes encoding secondary metabolites showed downregulation under manganese deficiency. Mn2+ deficiency also triggers upregulation of the cexA gene, which encodes the citrate exporter. We provide functional evidence that the upregulation of cexA is caused by the intracellular accumulation of citrate or acetyl-CoA and is a major factor in triggering citrate overflow. IMPORTANCE Citric acid is produced on industrial scale by batch fermentation of the filamentous fungus Aspergillus niger. High-yield citric acid production requires a low (<5 ppb) manganese(II) ion concentration in the culture broth. However, the requirement for this deficiency has not been investigated on a functional genomics level. Here, we compared the transcriptome of a citric acid hyper-producer A. niger strain grown under citric acid-producing conditions in 6-L scale bioreactors at Mn2+ ion-deficient (5 ppb) and Mn2+ ion-sufficient (100 ppb) conditions at three early time points of cultivation. We observed that Mn2+ deficiency triggers an upregulation of the citrate exporter gene cexA and provides functional evidence that this event is responsible for citrate overflow. In addition to the industrial relevance, this is the first study that examined the role of Mn2+ ion deficiency in a heterotrophic eukaryotic cell on a genome-wide scale.
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Affiliation(s)
- Erzsébet Fekete
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Vivien Bíró
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- University of Debrecen, Juhász-Nagy Pál Doctoral School of Biology and Environmental Sciences, Debrecen, Hungary
| | - Alexandra Márton
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- University of Debrecen, Juhász-Nagy Pál Doctoral School of Biology and Environmental Sciences, Debrecen, Hungary
| | - István Bakondi-Kovács
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- University of Debrecen, Juhász-Nagy Pál Doctoral School of Biology and Environmental Sciences, Debrecen, Hungary
| | - Erzsébet Sándor
- Institute of Food Science, Faculty of Agricultural and Food Science and Environmental Management, University of Debrecen, Debrecen, Hungary
| | - Béla Kovács
- Institute of Food Science, Faculty of Agricultural and Food Science and Environmental Management, University of Debrecen, Debrecen, Hungary
| | - Nicholas Geoffrion
- Centre for Structural and Functional Genomics, Concordia University, Montreal, Québec, Canada
| | - Adrian Tsang
- Centre for Structural and Functional Genomics, Concordia University, Montreal, Québec, Canada
| | - Christian P Kubicek
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria
| | - Levente Karaffa
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
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Thai HD, Trinh MT, Do LTBX, Le TH, Nguyen DT, Tran QT, Tran VKT, Mai LTD, Pham DN, Le DH, Vu TX, Tran VT. Gene function characterization in Aspergillus niger using a dual resistance marker transformation system mediated by Agrobacterium tumefaciens. J Microbiol Methods 2024; 224:106989. [PMID: 38996925 DOI: 10.1016/j.mimet.2024.106989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 06/14/2024] [Accepted: 07/09/2024] [Indexed: 07/14/2024]
Abstract
Aspergillus niger is a well-known workhorse for the industrial production of enzymes and organic acids. This fungus can also cause postharvest diseases in fruits. Although Agrobacterium tumefaciens-mediated transformation (ATMT) based on antibiotic resistance markers has been effectively exploited for inspecting functions of target genes in wild-type fungi, it still needs to be further improved in A. niger. In the present study, we re-examined the ATMT in the wild-type A. niger strains using the hygromycin resistance marker and introduced the nourseothricin resistance gene as a new selection marker for this fungus. Unexpectedly, our results revealed that the ATMT method using the resistance markers in A. niger led to numerous small colonies as false-positive transformants on transformation plates. Using the top agar overlay technique to restrict false positive colonies, a transformation efficiency of 87 ± 18 true transformants could be achieved for 106 conidia. With two different selection markers, we could perform both the deletion and complementation of a target gene in a single wild-type A. niger strain. Our results also indicated that two key regulatory genes (laeA and veA) of the velvet complex are required for A. niger to infect apple fruits. Notably, we demonstrated for the first time that a laeA homologous gene from the citrus postharvest pathogen Penicillium digitatum was able to restore the acidification ability and pathogenicity of the A. niger ΔlaeA mutant. The dual resistance marker ATMT system from our work represents an improved genetic tool for gene function characterization in A. niger.
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Affiliation(s)
- Hanh-Dung Thai
- National Key Laboratory of Enzyme and Protein Technology, University of Science, Vietnam National University, 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam
| | - Minh Thi Trinh
- National Key Laboratory of Enzyme and Protein Technology, University of Science, Vietnam National University, 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam
| | - Loc Thi Binh Xuan Do
- National Key Laboratory of Enzyme and Protein Technology, University of Science, Vietnam National University, 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam
| | - Thu-Hang Le
- National Key Laboratory of Enzyme and Protein Technology, University of Science, Vietnam National University, 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam
| | - Duc-Thanh Nguyen
- National Key Laboratory of Enzyme and Protein Technology, University of Science, Vietnam National University, 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam
| | - Que Thi Tran
- National Key Laboratory of Enzyme and Protein Technology, University of Science, Vietnam National University, 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam
| | - Van-Khanh Tong Tran
- National Key Laboratory of Enzyme and Protein Technology, University of Science, Vietnam National University, 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam
| | - Linh Thi Dam Mai
- Faculty of Biology, University of Science, Vietnam National University, 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam
| | - Duc-Ngoc Pham
- Faculty of Biology, University of Science, Vietnam National University, 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam
| | - Diep Hong Le
- Faculty of Biology, University of Science, Vietnam National University, 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam
| | - Tao Xuan Vu
- Center for Experimental Biology, National Center for Technological Progress, Ministry of Science and Technology of Vietnam, C6 Thanh Xuan Bac, Thanh Xuan, Hanoi, Viet Nam
| | - Van-Tuan Tran
- National Key Laboratory of Enzyme and Protein Technology, University of Science, Vietnam National University, 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam; Faculty of Biology, University of Science, Vietnam National University, 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam.
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3
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Guan J, Wang W, Zhang K, Shi X, Yang Q, Song J. Role of AplaeA in the regulation of spore production and poly(malic acid) synthesis in Aureobasidium pullulans. Int J Biol Macromol 2024; 279:135153. [PMID: 39214223 DOI: 10.1016/j.ijbiomac.2024.135153] [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: 05/12/2024] [Revised: 08/09/2024] [Accepted: 08/27/2024] [Indexed: 09/04/2024]
Abstract
Poly(malic acid) (PMLA) as one of the important metabolites in Aureobasidium pullulans has great application in a variety of fields. LaeA, a global regulator capable of controlling fungal secondary metabolites, has been identified in A. pullulans. The involvement of LaeA in the biosynthesis of PMLA through direct or indirect means and its role in A. pullulans is currently unknown. Here we extracted and characterized the AplaeA gene from A. pullulans HIT-LCY3T and resolved it by bioinformatics. The function of AplaeA was subsequently characterized by Rnai-LaeA and OEX-LaeA mutants. Based on phenotypic observations of the mutant strains, it was found that the gene had a large effect on the morphology and melanin production aspects of the strain, and that overexpression of the AplaeA gene resulted in a substantial increase in spore numbers. RT-qPCR combined with protein interactions results analyzed that ApLaeA positively regulates PMLA biosynthesis by controlling the expression of core genes of PMLA biosynthesis gene cluster and other related regulatory factors. Finally, OEX-LaeA was used as the starting strain to obtain the optimal fermentation conditions. These findings illustrate the regulatory mechanism of a hypothesized global regulator, LaeA, in A. pullulans HIT-LCY3T, suggesting its potential application in industrial-scale PMLA biosynthesis.
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Affiliation(s)
- Jiaqi Guan
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150006, China
| | - Wan Wang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150006, China
| | - Kai Zhang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150006, China
| | - Xinyue Shi
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150006, China
| | - Qian Yang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150006, China; State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Jinzhu Song
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150006, China.
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4
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Hou X, Liu L, Xu D, Lai D, Zhou L. Involvement of LaeA and Velvet Proteins in Regulating the Production of Mycotoxins and Other Fungal Secondary Metabolites. J Fungi (Basel) 2024; 10:561. [PMID: 39194887 DOI: 10.3390/jof10080561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2024] [Revised: 07/30/2024] [Accepted: 08/06/2024] [Indexed: 08/29/2024] Open
Abstract
Fungi are rich sources of secondary metabolites of agrochemical, pharmaceutical, and food importance, such as mycotoxins, antibiotics, and antitumor agents. Secondary metabolites play vital roles in fungal pathogenesis, growth and development, oxidative status modulation, and adaptation/resistance to various environmental stresses. LaeA contains an S-adenosylmethionine binding site and displays methyltransferase activity. The members of velvet proteins include VeA, VelB, VelC, VelD and VosA for each member with a velvet domain. LaeA and velvet proteins can form multimeric complexes such as VosA-VelB and VelB-VeA-LaeA. They belong to global regulators and are mainly impacted by light. One of their most important functions is to regulate gene expressions that are responsible for secondary metabolite biosynthesis. The aim of this mini-review is to represent the newest cognition of the biosynthetic regulation of mycotoxins and other fungal secondary metabolites by LaeA and velvet proteins. In most cases, LaeA and velvet proteins positively regulate production of fungal secondary metabolites. The regulated fungal species mainly belong to the toxigenic fungi from the genera of Alternaria, Aspergillus, Botrytis, Fusarium, Magnaporthe, Monascus, and Penicillium for the production of mycotoxins. We can control secondary metabolite production to inhibit the production of harmful mycotoxins while promoting the production of useful metabolites by global regulation of LaeA and velvet proteins in fungi. Furthermore, the regulation by LaeA and velvet proteins should be a practical strategy in activating silent biosynthetic gene clusters (BGCs) in fungi to obtain previously undiscovered metabolites.
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Affiliation(s)
- Xuwen Hou
- MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Liyao Liu
- MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Dan Xu
- MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Daowan Lai
- MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Ligang Zhou
- MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing 100193, China
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5
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Nie H, Zhang Y, Li M, Wang W, Wang Z, Zheng J. Expression of microbial lipase in filamentous fungus Aspergillus niger: a review. 3 Biotech 2024; 14:172. [PMID: 38841267 PMCID: PMC11147998 DOI: 10.1007/s13205-024-03998-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 04/28/2024] [Indexed: 06/07/2024] Open
Abstract
Lipase has high economic importance and is widely used in biodiesel, food, detergents, cosmetics, and pharmaceutical industries. The rapid development of synthetic biology and system biology has not only paved the way for comprehensively understanding the efficient operation mechanism of Aspergillus niger cell factories but also introduced a new technological system for creating and optimizing high-efficiency A. niger cell factories. In this review, all relevant data on microbial lipase enzyme sources and general properties are gathered and updated. The relationship between A. niger strain morphology and protein production is discussed. The safety of A. niger strain is investigated to ensure product safety. The biotechnologies and factors influencing lipase expression in A. niger are summarized. This review focuses on various strategies to improve lipase expression in A. niger. The summary of these methods and the application of the gene editing technology CRISPR/Cas9 system can further improve the efficiency of constructing the engineered lipase-producing A. niger.
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Affiliation(s)
- Hongmei Nie
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 China
| | - Yueting Zhang
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 China
| | - Mengjiao Li
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 China
| | - Weili Wang
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 China
| | - Zhao Wang
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 China
| | - Jianyong Zheng
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014 China
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6
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Książek E. Citric Acid: Properties, Microbial Production, and Applications in Industries. Molecules 2023; 29:22. [PMID: 38202605 PMCID: PMC10779990 DOI: 10.3390/molecules29010022] [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: 11/01/2023] [Revised: 12/11/2023] [Accepted: 12/15/2023] [Indexed: 01/12/2024] Open
Abstract
Citric acid finds broad applications in various industrial sectors, such as the pharmaceutical, food, chemical, and cosmetic industries. The bioproduction of citric acid uses various microorganisms, but the most commonly employed ones are filamentous fungi such as Aspergillus niger and yeast Yarrowia lipolytica. This article presents a literature review on the properties of citric acid, the microorganisms and substrates used, different fermentation techniques, its industrial utilization, and the global citric acid market. This review emphasizes that there is still much to explore, both in terms of production process techniques and emerging new applications of citric acid.
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Affiliation(s)
- Ewelina Książek
- Department of Agroenginieering and Quality Analysis, Faculty of Production Engineering, Wroclaw University of Economics and Business, Komandorska 118-120, 53-345 Wrocław, Poland
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7
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Nishitani A, Hiramatsu K, Kadooka C, Mori K, Okutsu K, Yoshizaki Y, Takamine K, Tashiro K, Goto M, Tamaki H, Futagami T. Expression of heterochromatin protein 1 affects citric acid production in Aspergillus luchuensis mut. kawachii. J Biosci Bioeng 2023; 136:443-451. [PMID: 37775438 DOI: 10.1016/j.jbiosc.2023.09.004] [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: 06/11/2023] [Revised: 08/17/2023] [Accepted: 09/07/2023] [Indexed: 10/01/2023]
Abstract
A putative methyltransferase, LaeA, controls citric acid production through epigenetic regulation of the citrate exporter gene, cexA, in the white koji fungus Aspergillus luchuensis mut. kawachii. In this study, we investigated the role of another epigenetic regulator, heterochromatin protein 1, HepA, in citric acid production. The ΔhepA strain exhibited reduced citric acid production in liquid culture, although to a lesser extent compared to the ΔlaeA strain. In addition, the ΔlaeA ΔhepA strain showed citric acid production similar to the ΔlaeA strain, indicating that HepA plays a role in citric acid production, albeit with a less-significant regulatory effect than LaeA. RNA-seq analysis revealed that the transcriptomic profiles of the ΔhepA and ΔlaeA strains were similar, and the expression level of cexA was reduced in both strains. These findings suggest that the genes regulated by HepA are similar to those regulated by LaeA in A. luchuensis mut. kawachii. However, the reductions in citric acid production and cexA expression observed in the disruptants were mitigated in rice koji, a solid-state culture. Thus, the mechanism by which citric acid production is regulated differs between liquid and solid cultivation. Further investigation is thus needed to understand the regulatory mechanism in koji.
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Affiliation(s)
- Atsushi Nishitani
- United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Center for Advanced Science Research and Promotion, Kagoshima University, Kagoshima 890-0065, Japan
| | - Kentaro Hiramatsu
- Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan
| | - Chihiro Kadooka
- Department of Biotechnology and Life Sciences, Faculty of Biotechnology and Life Sciences, Sojo University, Kumamoto 860-0082, Japan
| | - Kazuki Mori
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan
| | - Kayu Okutsu
- Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan; Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima 890-0065, Japan
| | - Yumiko Yoshizaki
- United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan; Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima 890-0065, Japan
| | - Kazunori Takamine
- United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan; Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima 890-0065, Japan
| | - Kosuke Tashiro
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan
| | - Masatoshi Goto
- United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Department of Applied Biochemistry and Food Science, Faculty of Agriculture, Saga University, Saga 840-8502, Japan
| | - Hisanori Tamaki
- United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan; Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima 890-0065, Japan
| | - Taiki Futagami
- United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima 890-0065, Japan; Graduate School of Agriculture, Forestry and Fisheries, Kagoshima University, Kagoshima 890-0065, Japan; Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima 890-0065, Japan.
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8
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Arentshorst M, Kooloth Valappil P, Mózsik L, Regensburg-Tuïnk TJG, Seekles SJ, Tjallinks G, Fraaije MW, Visser J, Ram AFJ. A CRISPR/Cas9-based multicopy integration system for protein production in Aspergillus niger. FEBS J 2023; 290:5127-5140. [PMID: 37335926 DOI: 10.1111/febs.16891] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/25/2023] [Accepted: 06/16/2023] [Indexed: 06/21/2023]
Abstract
The filamentous fungus Aspergillus niger is well known for its high protein secretion capacity and a preferred host for homologous and heterologous protein production. To improve the protein production capacity of A. niger even further, a set of dedicated protein production strains was made containing up to 10 glucoamylase landing sites (GLSs) at predetermined sites in the genome. These GLSs replace genes encoding enzymes abundantly present or encoding unwanted functions. Each GLS contains the promotor and terminator region of the glucoamylase gene (glaA), one of the highest expressed genes in A. niger. Integrating multiple gene copies, often realized by random integration, is known to boost protein production yields. In our approach the GLSs allow for rapid targeted gene replacement using CRISPR/Cas9-mediated genome editing. By introducing the same or different unique DNA sequences (dubbed KORE sequences) in each GLS and designing Cas9-compatible single guide RNAs, one is able to select at which GLS integration of a target gene occurs. In this way a set of identical strains with different copy numbers of the gene of interest can be easily and rapidly made to compare protein production levels. As an illustration of its potential, we successfully used the expression platform to generate multicopy A. niger strains producing the Penicillium expansum PatE::6xHis protein catalysing the final step in patulin biosynthesis. The A. niger strain expressing 10 copies of the patE::6xHis expression cassette produced about 70 μg·mL-1 PatE protein in the culture medium with a purity just under 90%.
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Affiliation(s)
- Mark Arentshorst
- Microbial Sciences, Fungal Genetics and Biotechnology, Institute of Biology Leiden, Leiden University, The Netherlands
| | - Prajeesh Kooloth Valappil
- Microbial Sciences, Fungal Genetics and Biotechnology, Institute of Biology Leiden, Leiden University, The Netherlands
| | - László Mózsik
- Microbial Sciences, Fungal Genetics and Biotechnology, Institute of Biology Leiden, Leiden University, The Netherlands
| | - Tonny J G Regensburg-Tuïnk
- Microbial Sciences, Fungal Genetics and Biotechnology, Institute of Biology Leiden, Leiden University, The Netherlands
| | - Sjoerd J Seekles
- Microbial Sciences, Fungal Genetics and Biotechnology, Institute of Biology Leiden, Leiden University, The Netherlands
| | - Gwen Tjallinks
- Molecular Enzymology, University of Groningen, The Netherlands
| | - Marco W Fraaije
- Molecular Enzymology, University of Groningen, The Netherlands
| | - Jaap Visser
- Microbial Sciences, Fungal Genetics and Biotechnology, Institute of Biology Leiden, Leiden University, The Netherlands
| | - Arthur F J Ram
- Microbial Sciences, Fungal Genetics and Biotechnology, Institute of Biology Leiden, Leiden University, The Netherlands
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9
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Mathieu Y, Raji O, Bellemare A, Di Falco M, Nguyen TTM, Viborg AH, Tsang A, Master E, Brumer H. Functional characterization of fungal lytic polysaccharide monooxygenases for cellulose surface oxidation. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:132. [PMID: 37679837 PMCID: PMC10486138 DOI: 10.1186/s13068-023-02383-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 08/14/2023] [Indexed: 09/09/2023]
Abstract
BACKGROUND Microbial lytic polysaccharide monooxygenases (LPMOs) cleave diverse biomass polysaccharides, including cellulose and hemicelluloses, by initial oxidation at C1 or C4 of glycan chains. Within the Carbohydrate-Active Enzymes (CAZy) classification, Auxiliary Activity Family 9 (AA9) comprises the first and largest group of fungal LPMOs, which are often also found in tandem with non-catalytic carbohydrate-binding modules (CBMs). LPMOs originally attracted attention for their ability to potentiate complete biomass deconstruction to monosaccharides. More recently, LPMOs have been applied for selective surface modification of insoluble cellulose and chitin. RESULTS To further explore the catalytic diversity of AA9 LPMOs, over 17,000 sequences were extracted from public databases, filtered, and used to construct a sequence similarity network (SSN) comprising 33 phylogenetically supported clusters. From these, 32 targets were produced successfully in the industrial filamentous fungus Aspergillus niger, 25 of which produced detectable LPMO activity. Detailed biochemical characterization of the eight most highly produced targets revealed individual C1, C4, and mixed C1/C4 regiospecificities of cellulose surface oxidation, different redox co-substrate preferences, and CBM targeting effects. Specifically, the presence of a CBM correlated with increased formation of soluble oxidized products and a more localized pattern of surface oxidation, as indicated by carbonyl-specific fluorescent labeling. On the other hand, LPMOs without native CBMs were associated with minimal release of soluble products and comparatively dispersed oxidation pattern. CONCLUSIONS This work provides insight into the structural and functional diversity of LPMOs, and highlights the need for further detailed characterization of individual enzymes to identify those best suited for cellulose saccharification versus surface functionalization toward biomaterials applications.
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Affiliation(s)
- Yann Mathieu
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, BC, V6T 1Z4, Canada
- BioProducts Institute, University of British Columbia, 2385 East Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Olanrewaju Raji
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON, M5S 3E5, Canada
| | - Annie Bellemare
- Centre for Structural & Functional Genomics, Concordia University, 7141 Sherbrooke-West Street, Montreal, H4B 1R6, Canada
| | - Marcos Di Falco
- Centre for Structural & Functional Genomics, Concordia University, 7141 Sherbrooke-West Street, Montreal, H4B 1R6, Canada
| | - Thi Truc Minh Nguyen
- Centre for Structural & Functional Genomics, Concordia University, 7141 Sherbrooke-West Street, Montreal, H4B 1R6, Canada
| | - Alexander Holm Viborg
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Adrian Tsang
- Centre for Structural & Functional Genomics, Concordia University, 7141 Sherbrooke-West Street, Montreal, H4B 1R6, Canada
| | - Emma Master
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON, M5S 3E5, Canada.
- Department of Bioproducts and Biosystems, Aalto University, Kemistintie 1, 02150, Espoo, Finland.
| | - Harry Brumer
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, BC, V6T 1Z4, Canada.
- BioProducts Institute, University of British Columbia, 2385 East Mall, Vancouver, BC, V6T 1Z4, Canada.
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1, Canada.
- Department of Biochemistry and Molecular Biology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada.
- Department of Botany, University of British Columbia, 3200 University Boulevard, Vancouver, BC, V6T 1Z4, Canada.
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Zhang Y, Wang X, Ran Y, Zhang KQ, Li GH. AfLaeA, a Global Regulator of Mycelial Growth, Chlamydospore Production, Pathogenicity, Secondary Metabolism, and Energy Metabolism in the Nematode-Trapping Fungus Arthrobotrys flagrans. Microbiol Spectr 2023; 11:e0018623. [PMID: 37358432 PMCID: PMC10434191 DOI: 10.1128/spectrum.00186-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 05/15/2023] [Indexed: 06/27/2023] Open
Abstract
Arthrobotrys flagrans (Duddingtonia flagrans) is a typical nematode-trapping fungus which has been used for nematode biocontrol. The global regulator LaeA is widely distributed in filamentous fungi and plays a crucial role in secondary metabolism and development in addition to pathogenicity in fungal pathogens. In this study, the chromosome-level genome of A. flagrans CBS 565.50 was sequenced and homologous sequences of LaeA were identified in A. flagrans. A. flagrans LaeA (AfLaeA) knockout resulted in slower hyphal growth and a smoother hyphal surface. Importantly, deletion of AfLaeA resulted in the absence of chlamydospores and attenuated glycogen and lipid accumulation in hyphae. Similarly, disruption of the AfLaeA gene led to fewer traps and electron-dense bodies, lower protease activity, and a delay in capturing nematodes. The AfLaeA gene had a large effect on the secondary metabolism of A. flagrans, and both the deletion and overexpression of AfLaeA could yield new compounds, whereas some compounds were lost due to the absence of the AfLaeA. Protein-protein interactions between AfLaeA and another eight proteins were detected. Furthermore, transcriptome data analysis showed that 17.77% and 35.51% of the genes were influenced by the AfLaeA gene on days 3 and 7, respectively. AfLaeA gene deletion resulted in the higher expression level of the artA gene cluster, and multiple differentially expressed genes involved in glycogen and lipid synthesis and metabolism showed opposite expression patterns in wild-type and ΔAfLaeA strains. In summary, our results provide novel insights into the functions of AfLaeA in mycelial growth, chlamydospore production, pathogenicity, secondary metabolism, and energy metabolism in A. flagrans. IMPORTANCE The regulation of biological functions, such as the secondary metabolism, development, and pathogenicity of LaeA, has been reported in multiple fungi. But to date, no study on LaeA in nematode-trapping fungi has been reported. Moreover, it has not been investigated whether or not LaeA is involved in energy metabolism and chlamydospore formation has not been investigated. Especially in the formation mechanism of chlamydospores, several transcription factors and signaling pathways are involved in the production of chlamydospores, but the mechanism of chlamydospore formation from an epigenetic perspective has not been revealed. Concurrently, an understanding of protein-protein interactions will provide a broader perspective on the regulatory mechanism of AfLaeA in A. flagrans. This finding is critical for understanding the regulatory role of AfLaeA in the biocontrol fungus A. flagrans and establishes a foundation for developing high-efficiency nematode biocontrol agents.
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Affiliation(s)
- Yu Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, China
| | - Xin Wang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, China
| | - Yuan Ran
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, China
| | - Ke-Qin Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, China
| | - Guo-Hong Li
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, China
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11
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Yuan G, Czajka JJ, Dai Z, Hu D, Pomraning KR, Hofstad BA, Kim J, Robles AL, Deng S, Magnuson JK. Rapid and robust squashed spore/colony PCR of industrially important fungi. Fungal Biol Biotechnol 2023; 10:15. [PMID: 37422681 DOI: 10.1186/s40694-023-00163-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 06/18/2023] [Indexed: 07/10/2023] Open
Abstract
BACKGROUND Fungi have been utilized for centuries in medical, agricultural, and industrial applications. Development of systems biology techniques has enabled the design and metabolic engineering of these fungi to produce novel fuels, chemicals, and enzymes from renewable feedstocks. Many genetic tools have been developed for manipulating the genome and creating mutants rapidly. However, screening and confirmation of transformants remain an inefficient step within the design, build, test, and learn cycle in many industrial fungi because extracting fungal genomic DNA is laborious, time-consuming, and involves toxic chemicals. RESULTS In this study we developed a rapid and robust technique called "Squash-PCR" to break open the spores and release fungal genomic DNA as a template for PCR. The efficacy of Squash-PCR was investigated in eleven different filamentous fungal strains. Clean PCR products with high yields were achieved in all tested fungi. Spore age and type of DNA polymerase did not affect the efficiency of Squash-PCR. However, spore concentration was found to be the crucial factor for Squash-PCR in Aspergillus niger, with the dilution of starting material often resulting in higher PCR product yield. We then further evaluated the applicability of the squashing procedure for nine different yeast strains. We found that Squash-PCR can be used to improve the quality and yield of colony PCR in comparison to direct colony PCR in the tested yeast strains. CONCLUSION The developed technique will enhance the efficiency of screening transformants and accelerate genetic engineering in filamentous fungi and yeast.
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Affiliation(s)
- Guoliang Yuan
- Chemical and Biological Processes Development Group, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
- DOE Agile BioFoundry, Emeryville, CA, 94608, USA
| | - Jeffrey J Czajka
- Chemical and Biological Processes Development Group, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
- DOE Agile BioFoundry, Emeryville, CA, 94608, USA
| | - Ziyu Dai
- Chemical and Biological Processes Development Group, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
- DOE Agile BioFoundry, Emeryville, CA, 94608, USA
| | - Dehong Hu
- Chemical and Biological Processes Development Group, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Kyle R Pomraning
- Chemical and Biological Processes Development Group, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
- DOE Agile BioFoundry, Emeryville, CA, 94608, USA
| | - Beth A Hofstad
- Chemical and Biological Processes Development Group, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
- DOE Agile BioFoundry, Emeryville, CA, 94608, USA
| | - Joonhoon Kim
- Chemical and Biological Processes Development Group, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
- DOE Agile BioFoundry, Emeryville, CA, 94608, USA
| | - Ana L Robles
- Chemical and Biological Processes Development Group, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
- DOE Agile BioFoundry, Emeryville, CA, 94608, USA
| | - Shuang Deng
- Chemical and Biological Processes Development Group, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
- DOE Agile BioFoundry, Emeryville, CA, 94608, USA.
| | - Jon K Magnuson
- Chemical and Biological Processes Development Group, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
- DOE Agile BioFoundry, Emeryville, CA, 94608, USA.
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12
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Thai HD, Do LTBX, Nguyen XT, Vu TX, Tran HTT, Nguyen HQ, Tran VT. A newly constructed Agrobacterium-mediated transformation system based on the hisB auxotrophic marker for genetic manipulation in Aspergillus niger. Arch Microbiol 2023; 205:183. [PMID: 37032362 DOI: 10.1007/s00203-023-03530-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 03/15/2023] [Accepted: 03/31/2023] [Indexed: 04/11/2023]
Abstract
The filamentous fungus Aspergillus niger is widely exploited as an industrial workhorse for producing enzymes and organic acids. So far, different genetic tools, including CRISPR/Cas9 genome editing strategies, have been developed for the engineering of A. niger. However, these tools usually require a suitable method for gene transfer into the fungal genome, like protoplast-mediated transformation (PMT) or Agrobacterium tumefaciens-mediated transformation (ATMT). Compared to PMT, ATMT is considered more advantageous because fungal spores can be used directly for genetic transformation instead of protoplasts. Although ATMT has been applied in many filamentous fungi, it remains less effective in A. niger. In the present study, we deleted the hisB gene and established an ATMT system for A. niger based on the histidine auxotrophic mechanism. Our results revealed that the ATMT system could achieve 300 transformants per 107 fungal spores under optimal transformation conditions. The ATMT efficiency in this work is 5 - 60 times higher than those of the previous ATMT studies in A. niger. The ATMT system was successfully applied to express the DsRed fluorescent protein-encoding gene from the Discosoma coral in A. niger. Furthermore, we showed that the ATMT system was efficient for gene targeting in A. niger. The deletion efficiency of the laeA regulatory gene using hisB as a selectable marker could reach 68 - 85% in A. niger strains. The ATMT system constructed in our work represents a promising genetic tool for heterologous expression and gene targeting in the industrially important fungus A. niger.
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Affiliation(s)
- Hanh-Dung Thai
- National Key Laboratory of Enzyme and Protein Technology, University of Science, Vietnam National University, Hanoi (VNU), 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam
- Faculty of Biology, University of Science, Vietnam National University, Hanoi (VNU), 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam
| | - Loc Thi Binh Xuan Do
- National Key Laboratory of Enzyme and Protein Technology, University of Science, Vietnam National University, Hanoi (VNU), 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam
| | - Xuan Thi Nguyen
- National Key Laboratory of Enzyme and Protein Technology, University of Science, Vietnam National University, Hanoi (VNU), 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam
| | - Tao Xuan Vu
- National Key Laboratory of Enzyme and Protein Technology, University of Science, Vietnam National University, Hanoi (VNU), 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam
- Center for Experimental Biology, National Center for Technological Progress, Ministry of Science and Technology, C6 Thanh Xuan Bac, Thanh Xuan, Hanoi, Viet Nam
| | - Huyen Thi Thanh Tran
- Faculty of Biology, University of Science, Vietnam National University, Hanoi (VNU), 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam
| | - Huy Quang Nguyen
- National Key Laboratory of Enzyme and Protein Technology, University of Science, Vietnam National University, Hanoi (VNU), 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam
- Faculty of Biology, University of Science, Vietnam National University, Hanoi (VNU), 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam
| | - Van-Tuan Tran
- National Key Laboratory of Enzyme and Protein Technology, University of Science, Vietnam National University, Hanoi (VNU), 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam.
- Faculty of Biology, University of Science, Vietnam National University, Hanoi (VNU), 334 Nguyen Trai, Thanh Xuan, Hanoi, Viet Nam.
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13
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Zhao Z, Gu S, Liu D, Liu D, Chen B, Li J, Tian C. The putative methyltransferase LaeA regulates mycelium growth and cellulase production in Myceliophthora thermophila. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:58. [PMID: 37013645 PMCID: PMC10071736 DOI: 10.1186/s13068-023-02313-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 03/28/2023] [Indexed: 04/05/2023]
Abstract
BACKGROUND Filamentous fungi with the ability to use complex carbon sources has been developed as platforms for biochemicals production. Myceliophthora thermophila has been developed as the cell factory to produce lignocellulolytic enzymes and plant biomass-based biofuels and biochemicals in biorefinery. However, low fungal growth rate and cellulose utilization efficiency are significant barriers to the satisfactory yield and productivity of target products, which needs our further exploration and improvement. RESULTS In this study, we comprehensively explored the roles of the putative methyltransferase LaeA in regulating mycelium growth, sugar consumption, and cellulases expression. Deletion of laeA in thermophile fungus Myceliophthora thermophila enhanced mycelium growth and glucose consumption significantly. Further exploration of LaeA regulatory network indicated that multiple growth regulatory factors (GRF) Cre-1, Grf-1, Grf-2, and Grf-3, which act as negative repressors of carbon metabolism, were regulated by LaeA in this fungus. We also determined that phosphoenolpyruvate carboxykinase (PCK) is the core node of the metabolic network related to fungal vegetative growth, of which enhancement partially contributed to the elevated sugar consumption and fungal growth of mutant ΔlaeA. Noteworthily, LaeA participated in regulating the expression of cellulase genes and their transcription regulator. ΔlaeA exhibited 30.6% and 5.5% increases in the peak values of extracellular protein and endo-glucanase activity, respectively, as compared to the WT strain. Furthermore, the global histone methylation assays indicated that LaeA is associated with modulating H3K9 methylation levels. The normal function of LaeA on regulating fungal physiology is dependent on methyltransferase activity. CONCLUSIONS The research presented in this study clarified the function and elucidated the regulatory network of LaeA in the regulation of fungal growth and cellulase production, which will significantly deepen our understanding about the regulation mechanism of LaeA in filamentous fungi and provides the new strategy for improvement the fermentation properties of industrial fungal strain by metabolic engineering.
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Affiliation(s)
- Zhen Zhao
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shuying Gu
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Defei Liu
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Dandan Liu
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Bingchen Chen
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Jingen Li
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.
| | - Chaoguang Tian
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.
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14
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Jo C, Zhang J, Tam JM, Church GM, Khalil AS, Segrè D, Tang TC. Unlocking the magic in mycelium: Using synthetic biology to optimize filamentous fungi for biomanufacturing and sustainability. Mater Today Bio 2023; 19:100560. [PMID: 36756210 PMCID: PMC9900623 DOI: 10.1016/j.mtbio.2023.100560] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 01/19/2023] [Accepted: 01/20/2023] [Indexed: 01/22/2023] Open
Abstract
Filamentous fungi drive carbon and nutrient cycling across our global ecosystems, through its interactions with growing and decaying flora and their constituent microbiomes. The remarkable metabolic diversity, secretion ability, and fiber-like mycelial structure that have evolved in filamentous fungi have been increasingly exploited in commercial operations. The industrial potential of mycelial fermentation ranges from the discovery and bioproduction of enzymes and bioactive compounds, the decarbonization of food and material production, to environmental remediation and enhanced agricultural production. Despite its fundamental impact in ecology and biotechnology, molds and mushrooms have not, to-date, significantly intersected with synthetic biology in ways comparable to other industrial cell factories (e.g. Escherichia coli,Saccharomyces cerevisiae, and Komagataella phaffii). In this review, we summarize a suite of synthetic biology and computational tools for the mining, engineering and optimization of filamentous fungi as a bioproduction chassis. A combination of methods across genetic engineering, mutagenesis, experimental evolution, and computational modeling can be used to address strain development bottlenecks in established and emerging industries. These include slow mycelium growth rate, low production yields, non-optimal growth in alternative feedstocks, and difficulties in downstream purification. In the scope of biomanufacturing, we then detail previous efforts in improving key bottlenecks by targeting protein processing and secretion pathways, hyphae morphogenesis, and transcriptional control. Bringing synthetic biology practices into the hidden world of molds and mushrooms will serve to expand the limited panel of host organisms that allow for commercially-feasible and environmentally-sustainable bioproduction of enzymes, chemicals, therapeutics, foods, and materials of the future.
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Affiliation(s)
- Charles Jo
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
- Biological Design Center, Boston University, Boston, MA, USA
| | - Jing Zhang
- Biological Design Center, Boston University, Boston, MA, USA
- Graduate Program in Bioinformatics, Boston, MA, USA
| | - Jenny M. Tam
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - George M. Church
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - Ahmad S. Khalil
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
- Biological Design Center, Boston University, Boston, MA, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - Daniel Segrè
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
- Biological Design Center, Boston University, Boston, MA, USA
- Graduate Program in Bioinformatics, Boston, MA, USA
- Department of Biology, Boston University, Boston, MA, USA
- Department of Physics, Boston University, Boston, MA, USA
| | - Tzu-Chieh Tang
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
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15
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Wang X, Jarmusch SA, Frisvad JC, Larsen TO. Current status of secondary metabolite pathways linked to their related biosynthetic gene clusters in Aspergillus section Nigri. Nat Prod Rep 2023; 40:237-274. [PMID: 35587705 DOI: 10.1039/d1np00074h] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Covering: up to the end of 2021Aspergilli are biosynthetically 'talented' micro-organisms and therefore the natural products community has continually been interested in the wealth of biosynthetic gene clusters (BGCs) encoding numerous secondary metabolites related to these fungi. With the rapid increase in sequenced fungal genomes combined with the continuous development of bioinformatics tools such as antiSMASH, linking new structures to unknown BGCs has become much easier when taking retro-biosynthetic considerations into account. On the other hand, in most cases it is not as straightforward to prove proposed biosynthetic pathways due to the lack of implemented genetic tools in a given fungal species. As a result, very few secondary metabolite biosynthetic pathways have been characterized even amongst some of the most well studied Aspergillus spp., section Nigri (black aspergilli). This review will cover all known biosynthetic compound families and their structural diversity known from black aspergilli. We have logically divided this into sub-sections describing major biosynthetic classes (polyketides, non-ribosomal peptides, terpenoids, meroterpenoids and hybrid biosynthesis). Importantly, we will focus the review on metabolites which have been firmly linked to their corresponding BGCs.
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Affiliation(s)
- Xinhui Wang
- DTU Bioengineering, Technical University of Denmark, DK-2800, Kgs. Lyngby, Denmark.
| | - Scott A Jarmusch
- DTU Bioengineering, Technical University of Denmark, DK-2800, Kgs. Lyngby, Denmark.
| | - Jens C Frisvad
- DTU Bioengineering, Technical University of Denmark, DK-2800, Kgs. Lyngby, Denmark.
| | - Thomas O Larsen
- DTU Bioengineering, Technical University of Denmark, DK-2800, Kgs. Lyngby, Denmark.
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16
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Itaconic acid production is regulated by LaeA in Aspergillus pseudoterreus. Metab Eng Commun 2022; 15:e00203. [PMID: 36065328 PMCID: PMC9440423 DOI: 10.1016/j.mec.2022.e00203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 07/08/2022] [Accepted: 08/15/2022] [Indexed: 11/22/2022] Open
Abstract
The global regulator LaeA controls secondary metabolism in diverse Aspergillus species. Here we explored its role in regulation of itaconic acid production in Aspergillus pseudoterreus. To understand its role in regulating metabolism, we deleted and overexpressed laeA, and assessed the transcriptome, proteome, and secreted metabolome prior to and during initiation of phosphate limitation induced itaconic acid production. We found that secondary metabolite clusters, including the itaconic acid biosynthetic gene cluster, are regulated by laeA and that laeA is required for high yield production of itaconic acid. Overexpression of LaeA improves itaconic acid yield at the expense of biomass by increasing the expression of key biosynthetic pathway enzymes and attenuating the expression of genes involved in phosphate acquisition and scavenging. Increased yield was observed in optimized conditions as well as conditions containing excess nutrients that may be present in inexpensive sugar containing feedstocks such as excess phosphate or complex nutrient sources. This suggests that global regulators of metabolism may be useful targets for engineering metabolic flux that is robust to environmental heterogeneity. The Itaconic acid biosynthetic gene cluster is regulated by laeA. LaeA is required for production of itaconic acid. Overexpression of laeA attenuates genes involved in phosphate acquisition. Global regulator engineering increases robustness of itaconic acid production.
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17
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Valladares-Diestra KK, Porto de Souza Vandenberghe L, Soccol CR. Integrated xylooligosaccharides production from imidazole-treated sugarcane bagasse with application of in house produced enzymes. BIORESOURCE TECHNOLOGY 2022; 362:127800. [PMID: 36007765 DOI: 10.1016/j.biortech.2022.127800] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 08/15/2022] [Accepted: 08/16/2022] [Indexed: 06/15/2023]
Abstract
The application of biorefinery concepts to produce different value-added biomolecules such as xylooligosaccharides (XOs) generates economical competitive, sustainable and environmentally friendly processes. The objective of this work was to develop an efficient imidazole-pretreatment process of sugarcane bagasse (SB) and the use of the obtained hemicellulose fraction in the production of XOs with the application of in house produced xylanolytic enzymes using SB as substrate, under a biorefinery approach. SB imidazole pretreatment allowed the recovery of a hemicellulose rich fraction (34%) with 91.2% of delignification. Xylanase production by Aspergillus niger reached 53.1 U·mL-1 at 120 h. The application of produced xylanases in the enzymatic hydrolysis of extracted xylan, allowed the production of 6.06 g·L-1 of XOs, where xylotriose represented >70%. Great perspectives are viewed for the implementation of mixed processes in a sustainable closed cycle to produce biomolecules with concomitant valorization of subproducts from SB chain.
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Affiliation(s)
- Kim Kley Valladares-Diestra
- Bioprocess Engineering and Biotechnology Department, Federal University of Paraná, Centro Politécnico, CP 19011, Curitiba-PR 81531-980, Brazil
| | - Luciana Porto de Souza Vandenberghe
- Bioprocess Engineering and Biotechnology Department, Federal University of Paraná, Centro Politécnico, CP 19011, Curitiba-PR 81531-980, Brazil.
| | - Carlos Ricardo Soccol
- Bioprocess Engineering and Biotechnology Department, Federal University of Paraná, Centro Politécnico, CP 19011, Curitiba-PR 81531-980, Brazil
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18
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LaeA regulates morphological development and ochratoxin A biosynthesis in Aspergillus niger. Mycotoxin Res 2022; 38:221-229. [PMID: 35879501 DOI: 10.1007/s12550-022-00463-1] [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: 01/14/2022] [Revised: 07/01/2022] [Accepted: 07/19/2022] [Indexed: 10/16/2022]
Abstract
The global regulator LaeA and its orthologs govern the morphogenetic development and secondary metabolism of several filamentous ascomycetes. In Aspergillus niger, it has been shown that an LaeA ortholog (AnLaeA) regulates the production of citric acid and secondary metabolites. In this work, we constructed AnlaeA disruption and overexpression strains to investigate the roles of AnLaeA in morphological development and ochratoxin A (OTA) biosynthesis in A. niger. Phenotypic observation, chemical analysis, and gene expression analysis indicated that AnLaeA acts as a negative regulator of conidial morphogenesis and positively regulates gene expression of the OTA cluster in A. niger grown in CYA medium. However, it was observed that the upregulation of gene expression of the OTA cluster does not necessarily increase OTA production. Our results contribute to a better understanding of the AnlaeA regulatory mechanism and suggest the AnlaeA gene as a potential target for developing control strategies for A. niger infection and OTA biosynthesis.
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19
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Futagami T. The white koji fungus Aspergillus luchuensis mut. kawachii. Biosci Biotechnol Biochem 2022; 86:574-584. [PMID: 35238900 DOI: 10.1093/bbb/zbac033] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 02/24/2022] [Indexed: 11/13/2022]
Abstract
The white koji fungus, Aspergillus luchuensis mut. kawachii, is used in the production of shochu, a traditional Japanese distilled spirit. White koji fungus plays an important role in the shochu production process by supplying amylolytic enzymes such as α-amylase and glucoamylase. These enzymes convert starch contained in primary ingredients such as rice, barley, buckwheat, and sweet potato into glucose, which is subsequently utilized by the yeast Saccharomyces cerevisiae to produce ethanol. White koji fungus also secretes large amounts of citric acid, which lowers the pH of the shochu mash, thereby preventing the growth of undesired microbes and enabling stable production of shochu in relatively warm regions of Japan. This review describes the historical background, research tools, and recent advances in studies of the mechanism of citric acid production by white koji fungus.
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Affiliation(s)
- Taiki Futagami
- Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima, Japan.,United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima, Japan
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20
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Ashton GD, Sang F, Blythe M, Zadik D, Holmes N, Malla S, Camps SMT, Wright V, Melchers WJG, Verweij PE, Dyer PS. Use of Bulk Segregant Analysis for Determining the Genetic Basis of Azole Resistance in the Opportunistic Pathogen Aspergillus fumigatus. Front Cell Infect Microbiol 2022; 12:841138. [PMID: 35531335 PMCID: PMC9069965 DOI: 10.3389/fcimb.2022.841138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 03/03/2022] [Indexed: 12/19/2022] Open
Abstract
A sexual cycle was described in 2009 for the opportunistic fungal pathogen Aspergillus fumigatus, opening up for the first time the possibility of using techniques reliant on sexual crossing for genetic analysis. The present study was undertaken to evaluate whether the technique 'bulk segregant analysis' (BSA), which involves detection of differences between pools of progeny varying in a particular trait, could be applied in conjunction with next-generation sequencing to investigate the underlying basis of monogenic traits in A. fumigatus. Resistance to the azole antifungal itraconazole was chosen as a model, with a dedicated bioinformatic pipeline developed to allow identification of SNPs that differed between the resistant progeny pool and resistant parent compared to the sensitive progeny pool and parent. A clinical isolate exhibiting monogenic resistance to itraconazole of unknown basis was crossed to a sensitive parent and F1 progeny used in BSA. In addition, the use of backcrossing and increasing the number in progeny pools was evaluated as ways to enhance the efficiency of BSA. Use of F1 pools of 40 progeny led to the identification of 123 candidate genes with SNPs distributed over several contigs when aligned to an A1163 reference genome. Successive rounds of backcrossing enhanced the ability to identify specific genes and a genomic region, with BSA of progeny (using 40 per pool) from a third backcross identifying 46 genes with SNPs, and BSA of progeny from a sixth backcross identifying 20 genes with SNPs in a single 292 kb region of the genome. The use of an increased number of 80 progeny per pool also increased the resolution of BSA, with 29 genes demonstrating SNPs between the different sensitive and resistant groupings detected using progeny from just the second backcross with the majority of variants located on the same 292 kb region. Further bioinformatic analysis of the 292 kb region identified the presence of a cyp51A gene variant resulting in a methionine to lysine (M220K) change in the CYP51A protein, which was concluded to be the causal basis of the observed resistance to itraconazole. The future use of BSA in genetic analysis of A. fumigatus is discussed.
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Affiliation(s)
- George D. Ashton
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Fei Sang
- DeepSeq, Centre for Genetics and Genomics, Queen’s Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Martin Blythe
- DeepSeq, Centre for Genetics and Genomics, Queen’s Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Daniel Zadik
- DeepSeq, Centre for Genetics and Genomics, Queen’s Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Nadine Holmes
- DeepSeq, Centre for Genetics and Genomics, Queen’s Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Sunir Malla
- DeepSeq, Centre for Genetics and Genomics, Queen’s Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Simone M. T. Camps
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Victoria Wright
- DeepSeq, Centre for Genetics and Genomics, Queen’s Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Willem J. G. Melchers
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Paul E. Verweij
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Paul S. Dyer
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
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21
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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: 26] [Impact Index Per Article: 8.7] [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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22
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Valladares-Diestra KK, Porto de Souza Vandenberghe L, Soccol CR. A biorefinery approach for enzymatic complex production for the synthesis of xylooligosaccharides from sugarcane bagasse. BIORESOURCE TECHNOLOGY 2021; 333:125174. [PMID: 33892428 DOI: 10.1016/j.biortech.2021.125174] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/07/2021] [Accepted: 04/09/2021] [Indexed: 06/12/2023]
Abstract
The use of low-cost feedstock for enzyme production is an environmental and economic solution. Sugarcane bagasse and soybean meal are employed in this study for optimised xylanase production with the concomitant synthesis of proteases. The enzymatic complex is produced by submerged fermentation by Aspergillus niger. Optimisation steps lead to a 2.16-fold increase in enzymatic activity. The fermentation kinetics are studied in Erlenmeyer flasks, a stirred tank reactor and a bubble column reactor, with the xylanase activities reaching 52.9; 33.7 and 60.5 U.mL-1, respectively. The protease production profile is also better in the bubble column reactor, exceeding 7 U.mL-1. The enzyme complex is then evaluated for the synthesis of xylooligosaccharides from sugarcane extracted xylan with a production of 3.1 g.L-1 where xylotriose is the main product. Excellent perspectives are observed for the developed process with potential applications in the animal feed, prebiotics and paper industries.
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Affiliation(s)
- Kim Kley Valladares-Diestra
- Bioprocess Engineering and Biotechnology Department, Federal University of Paraná, Brazil, Centro Politécnico, CP 19011, Curitiba-PR 81531-980, Brazil
| | - Luciana Porto de Souza Vandenberghe
- Bioprocess Engineering and Biotechnology Department, Federal University of Paraná, Brazil, Centro Politécnico, CP 19011, Curitiba-PR 81531-980, Brazil.
| | - Carlos Ricardo Soccol
- Bioprocess Engineering and Biotechnology Department, Federal University of Paraná, Brazil, Centro Politécnico, CP 19011, Curitiba-PR 81531-980, Brazil
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23
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Something old, something new: challenges and developments in Aspergillus niger biotechnology. Essays Biochem 2021; 65:213-224. [PMID: 33955461 PMCID: PMC8314004 DOI: 10.1042/ebc20200139] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/17/2021] [Accepted: 03/19/2021] [Indexed: 12/12/2022]
Abstract
The filamentous ascomycete fungus Aspergillus niger is a prolific secretor of organic acids, proteins, enzymes and secondary metabolites. Throughout the last century, biotechnologists have developed A. niger into a multipurpose cell factory with a product portfolio worth billions of dollars each year. Recent technological advances, from genome editing to other molecular and omics tools, promise to revolutionize our understanding of A. niger biology, ultimately to increase efficiency of existing industrial applications or even to make entirely new products. However, various challenges to this biotechnological vision, many several decades old, still limit applications of this fungus. These include an inability to tightly control A. niger growth for optimal productivity, and a lack of high-throughput cultivation conditions for mutant screening. In this mini-review, we summarize the current state-of-the-art for A. niger biotechnology with special focus on organic acids (citric acid, malic acid, gluconic acid and itaconic acid), secreted proteins and secondary metabolites, and discuss how new technological developments can be applied to comprehensively address a variety of old and persistent challenges.
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24
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Demirci E, Arentshorst M, Yilmaz B, Swinkels A, Reid ID, Visser J, Tsang A, Ram AFJ. Genetic Characterization of Mutations Related to Conidiophore Stalk Length Development in Aspergillus niger Laboratory Strain N402. Front Genet 2021; 12:666684. [PMID: 33959152 PMCID: PMC8093798 DOI: 10.3389/fgene.2021.666684] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 03/29/2021] [Indexed: 11/29/2022] Open
Abstract
Aspergillus niger is an important filamentous fungus in industrial biotechnology for the production of citric acid and enzymes. In the late 1980s, the A. niger N400/NRRL3 strain was selected for both fundamental and applied studies in relation to several processes including gluconic acid and protein production. To facilitate handling of A. niger, the N400 wild-type strain was UV mutagenized in two consecutive rounds to generate N401 and N402. N402 was used as a reference laboratory strain and exhibits the phenotypes with reduced conidiophore stalk length and reduced radial growth. The conidiophore stalk length and radial growth of A. niger strain N400 were determined and compared to N401 and N402. The length of N400 conidiophore stalks (2.52 ± 0.40 mm) was reduced in N401 and N402 to 0.66 ± 0.14 mm and 0.34 ± 0.06 mm, respectively. Whereas N400 reached a colony diameter of 6.7 ± 0.2 cm after 7 days, N401 and N402 displayed reduced radial growth phenotype (4.3 ± 0.1 and 4.1 ± 0.1, respectively). To identify the mutations (dubbed cspA and cspB) responsible for the phenotypes of N401 and N402, the genomes were sequenced and compared to the N400 genome sequence. A parasexual cross was performed between N400 and N402 derivatives to isolate segregants which allowed cosegregation analysis of single nucleotide polymorphisms and insertions and deletions among the segregants. The shorter conidiophore stalk and reduced radial growth in N401 (cspA) was found to be caused by a 9-kb deletion on chromosome III and was further narrowed down to a truncation of NRRL3_03857 which encodes a kinesin-like protein homologous to the A. nidulans UncA protein. The mutation responsible for the further shortening of conidiophore stalks in N402 (cspB) was found to be caused by a missense mutation on chromosome V in a hitherto unstudied C2H2 transcription factor encoded by the gene NRRL3_06646. The importance of these two genes in relation to conidiophore stalk length and radial growth was confirmed by single and double gene deletion studies. The mutations in the laboratory strain N402 should be taken into consideration when studying phenotypes in the N402 background.
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Affiliation(s)
- Ebru Demirci
- Institute of Biology Leiden, Microbial Sciences, Leiden University, Leiden, Netherlands
| | - Mark Arentshorst
- Institute of Biology Leiden, Microbial Sciences, Leiden University, Leiden, Netherlands
| | - Baran Yilmaz
- Institute of Biology Leiden, Microbial Sciences, Leiden University, Leiden, Netherlands
| | - Aram Swinkels
- Institute of Biology Leiden, Microbial Sciences, Leiden University, Leiden, Netherlands
| | - Ian D Reid
- Centre for Structural and Functional Genomics, Concordia University, Montreal, QC, Canada
| | - Jaap Visser
- Institute of Biology Leiden, Microbial Sciences, Leiden University, Leiden, Netherlands.,Fungal Genetics and Technology Consultancy, Wageningen, Netherlands
| | - Adrian Tsang
- Centre for Structural and Functional Genomics, Concordia University, Montreal, QC, Canada
| | - Arthur F J Ram
- Institute of Biology Leiden, Microbial Sciences, Leiden University, Leiden, Netherlands
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25
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Wang B, Li X, Tabudravu J, Wang S, Deng H, Pan L. The chemical profile of activated secondary metabolites by overexpressing LaeA in Aspergillus niger. Microbiol Res 2021; 248:126735. [PMID: 33706119 DOI: 10.1016/j.micres.2021.126735] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 02/04/2021] [Accepted: 02/20/2021] [Indexed: 11/19/2022]
Abstract
Although the mechanisms of regulating secondary metabolism by LaeA remains unclear, the synthesis of many secondary metabolites (SMs) in Aspergilli could be activated by LaeA mutation. In our previous sutdy, RNA-seq data has showed that the transcriptional level of many SM backbone genes could be upregulated by overexpressing LaeA. Herein, we analyzed the chemical profile of activated secondary metabolites in the variant of A. niger FGSC A1279 by overexpressing LaeA (OElaeA). 14 compounds were activated in A. niger FGSC A1279 OElaeA variant in the WATM medium. Chemical workup of organic extracts of the culture broth from the A. niger OElaeA mutant identified three pure compounds, flaviolin, orlandin and kotanin. The structures of these compounds were confirmed by HR-ESIMS, 1D/2D NMR, and computer assisted structure elucidation (CASE). Based on homologous alignment and comparison of literatures, the biosynthetic gene cluster (fla) of flaviolin was identified. The in vivo function of the backbone gene, flaA, encoding a multidomain non-reducing polyketide synthase (SAT-KS-AT-PT-ACP), was verified via gene knockout and chemical analysis. Finally, a biosynthetic model for fungal flaviolin was proposed.
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Affiliation(s)
- Bin Wang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China; Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China
| | - Xuejie Li
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China; Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China
| | - Jioji Tabudravu
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen, AB24 3UE, Scotland, UK; School of Forensic and Applied Sciences, Faculty of Science & Technology, University of Central Lancashire, Preston, Lancashire, PR1 2HE, UK
| | - Shan Wang
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen, AB24 3UE, Scotland, UK
| | - Hai Deng
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen, AB24 3UE, Scotland, UK.
| | - Li Pan
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China; Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China.
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26
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Baker SE. Grand Challenges in Fungal Biotechnology. FRONTIERS IN FUNGAL BIOLOGY 2020; 1:626551. [PMID: 37743876 PMCID: PMC10512378 DOI: 10.3389/ffunb.2020.626551] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 11/17/2020] [Indexed: 09/26/2023]
Affiliation(s)
- Scott E. Baker
- Joint BioEnergy Institute, Emeryville, CA, United States
- Functional and Systems Biology Group, Environmental Molecular Sciences Division, Pacific Northwest National Laboratory, Richland, WA, United States
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27
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van Leeuwe TM, Arentshorst M, Forn-Cuní G, Geoffrion N, Tsang A, Delvigne F, Meijer AH, Ram AFJ, Punt PJ. Deletion of the Aspergillus niger Pro-Protein Processing Protease Gene kexB Results in a pH-Dependent Morphological Transition during Submerged Cultivations and Increases Cell Wall Chitin Content. Microorganisms 2020; 8:E1918. [PMID: 33276589 PMCID: PMC7761569 DOI: 10.3390/microorganisms8121918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 11/30/2020] [Accepted: 11/30/2020] [Indexed: 11/23/2022] Open
Abstract
There is a growing interest in the use of post-fermentation mycelial waste to obtain cell wall chitin as an added-value product. In the pursuit to identify suitable production strains that can be used for post-fermentation cell wall harvesting, we turned to an Aspergillus niger strain in which the kexB gene was deleted. Previous work has shown that the deletion of kexB causes hyper-branching and thicker cell walls, traits that may be beneficial for the reduction in fermentation viscosity and lysis. Hyper-branching of ∆kexB was previously found to be pH-dependent on solid medium at pH 6.0, but was absent at pH 5.0. This phenotype was reported to be less pronounced during submerged growth. Here, we show a series of controlled batch cultivations at a pH range of 5, 5.5, and 6 to examine the pellet phenotype of ΔkexB in liquid medium. Morphological analysis showed that ΔkexB formed wild type-like pellets at pH 5.0, whereas the hyper-branching ΔkexB phenotype was found at pH 6.0. The transition of phenotypic plasticity was found in cultivations at pH 5.5, seen as an intermediate phenotype. Analyzing the cell walls of ΔkexB from these controlled pH-conditions showed an increase in chitin content compared to the wild type across all three pH values. Surprisingly, the increase in chitin content was found to be irrespective of the hyper-branching morphology. Evidence for alterations in cell wall make-up are corroborated by transcriptional analysis that showed a significant cell wall stress response in addition to the upregulation of genes encoding other unrelated cell wall biosynthetic genes.
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Affiliation(s)
- Tim M. van Leeuwe
- Institute of Biology Leiden, Microbial Sciences, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands; (T.M.v.L.); (M.A.); (P.J.P.)
| | - Mark Arentshorst
- Institute of Biology Leiden, Microbial Sciences, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands; (T.M.v.L.); (M.A.); (P.J.P.)
| | - Gabriel Forn-Cuní
- Institute of Biology Leiden, Animal Sciences, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands; (G.F.-C.); (A.H.M.)
| | - Nicholas Geoffrion
- Centre for Structural and Functional Genomics, Concordia University, Montreal, QC H4B1R6, Canada; (N.G.); (A.T.)
| | - Adrian Tsang
- Centre for Structural and Functional Genomics, Concordia University, Montreal, QC H4B1R6, Canada; (N.G.); (A.T.)
| | - Frank Delvigne
- TERRA Teaching and Research Centre, Gembloux Agro-Bio Tech, University of Liège, Avenue de la Faculté, 2B, 5030 Gembloux, Belgium;
| | - Annemarie H. Meijer
- Institute of Biology Leiden, Animal Sciences, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands; (G.F.-C.); (A.H.M.)
| | - Arthur F. J. Ram
- Institute of Biology Leiden, Microbial Sciences, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands; (T.M.v.L.); (M.A.); (P.J.P.)
| | - Peter J. Punt
- Institute of Biology Leiden, Microbial Sciences, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands; (T.M.v.L.); (M.A.); (P.J.P.)
- Dutch DNA Biotech, Hugo R Kruytgebouw 4-Noord, Padualaan 8, 3584 CH Utrecht, The Netherlands
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Xu Y, Zhou Y, Cao W, Liu H. Improved Production of Malic Acid in Aspergillus niger by Abolishing Citric Acid Accumulation and Enhancing Glycolytic Flux. ACS Synth Biol 2020; 9:1418-1425. [PMID: 32379964 DOI: 10.1021/acssynbio.0c00096] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Microbial fermentation was widely explored to produce malic acid. Previously, Aspergillus niger has been successfully engineered, and a high titer of malic acid was achieved with strain S575, but it also produced a high level of byproduct citric acid. Here, the capability of A. niger in malic acid biosynthesis was further improved by eliminating the accumulation of citric acid and enhancing glycolytic flux. Characterization of variant mutants suggested that disruption of cexA, a gene encoding citric acid transporter located on cell membrane, abolished citric acid accumulation. However, cexA-deficient strain S895 showed significantly decreased malic acid production. Further analysis of S895 indicated that the transcription level of genes involved in glucose transportation and glycolytic pathway was significantly reduced, and the corresponding enzyme activity was also lower than those of S575. Individual overexpression of genes encoding glucose transporter MstC and key enzymes (hexokinase HxkA, 6-phosphofructo-2-kinase PfkA, and pyruvate kinase PkiA) involved in irreversible reactions of glycolic pathway increased malic acid production. Accordingly, genes of mstC, hxkA, pfkA, and pkiA were overexpressed altogether in S895, and the resultant strain S1149 was constructed. The titer of malic acid in fed-batch fermentation with S1149 reached 201.13 g/L. Compared with S575, the byproduct of citric acid was completely abolished in S1149, and the ratio of malic acid/glucose was increased from 1.27 to 1.64 mol/mol, the highest yield reported so far, and the fermentation period was shortened from 9 to 8 days. Thus, a strain with great industrial application potential was developed by engineering nine genes in A. niger, and a pilot fermentation technology was exploited.
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Affiliation(s)
- Yongxue Xu
- MOE Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science & Technology, 300457 Tianjin, China
| | - Yutao Zhou
- MOE Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science & Technology, 300457 Tianjin, China
| | - Wei Cao
- MOE Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science & Technology, 300457 Tianjin, China
- Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin University of Science & Technology, 300457 Tianjin, China
| | - Hao Liu
- MOE Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science & Technology, 300457 Tianjin, China
- Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin University of Science & Technology, 300457 Tianjin, China
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Jørgensen TR, Burggraaf AM, Arentshorst M, Schutze T, Lamers G, Niu J, Kwon MJ, Park J, Frisvad JC, Nielsen KF, Meyer V, van den Hondel CA, Dyer PS, Ram AF. Identification of SclB, a Zn(II)2Cys6 transcription factor involved in sclerotium formation in Aspergillus niger. Fungal Genet Biol 2020; 139:103377. [DOI: 10.1016/j.fgb.2020.103377] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 02/07/2020] [Accepted: 02/14/2020] [Indexed: 10/24/2022]
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30
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Miyamoto A, Kadooka C, Mori K, Tagawa Y, Okutsu K, Yoshizaki Y, Takamine K, Goto M, Tamaki H, Futagami T. Sirtuin SirD is involved in α-amylase activity and citric acid production in Aspergillus luchuensis mut. kawachii during a solid-state fermentation process. J Biosci Bioeng 2020; 129:454-466. [DOI: 10.1016/j.jbiosc.2019.11.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 11/01/2019] [Accepted: 11/11/2019] [Indexed: 11/28/2022]
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LaeA Controls Citric Acid Production through Regulation of the Citrate Exporter-Encoding cexA Gene in Aspergillus luchuensis mut. kawachii. Appl Environ Microbiol 2020; 86:AEM.01950-19. [PMID: 31862728 DOI: 10.1128/aem.01950-19] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 12/17/2019] [Indexed: 11/20/2022] Open
Abstract
The putative methyltransferase LaeA is a global regulator of metabolic and development processes in filamentous fungi. We characterized the homologous laeA genes of the white koji fungus Aspergillus luchuensis mut. kawachii (A. kawachii) to determine their role in citric acid hyperproduction. The ΔlaeA strain exhibited a significant reduction in citric acid production. Cap analysis gene expression (CAGE) revealed that laeA is required for the expression of a putative citrate exporter-encoding cexA gene, which is critical for citric acid production. Deficient citric acid production by a ΔlaeA strain was rescued by the overexpression of cexA to a level comparable with that of a cexA-overexpressing ΔcexA strain. In addition, chromatin immunoprecipitation coupled with quantitative PCR (ChIP-qPCR) analysis indicated that LaeA regulates the expression of cexA via methylation levels of the histones H3K4 and H3K9. These results indicate that LaeA is involved in citric acid production through epigenetic regulation of cexA in A. kawachii IMPORTANCE A. kawachii has been traditionally used for production of the distilled spirit shochu in Japan. Citric acid produced by A. kawachii plays an important role in preventing microbial contamination during the shochu fermentation process. This study characterized homologous laeA genes; using CAGE, complementation tests, and ChIP-qPCR, it was found that laeA is required for citric acid production through the regulation of cexA in A. kawachii The epigenetic regulation of citric acid production elucidated in this study will be useful for controlling the fermentation processes of shochu.
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A newly constructed Agrobacterium-mediated transformation system revealed the influence of nitrogen sources on the function of the LaeA regulator in Penicillium chrysogenum. Fungal Biol 2019; 123:830-842. [DOI: 10.1016/j.funbio.2019.08.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/20/2019] [Accepted: 08/28/2019] [Indexed: 01/02/2023]
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33
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Filamentous fungi for the production of enzymes, chemicals and materials. Curr Opin Biotechnol 2019; 59:65-70. [DOI: 10.1016/j.copbio.2019.02.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 01/28/2019] [Accepted: 02/09/2019] [Indexed: 02/02/2023]
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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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35
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Zhgun AA, Nuraeva GK, Dumina MV, Voinova TM, Dzhavakhiya VV, Eldarov MA. 1,3-Diaminopropane and Spermidine Upregulate Lovastatin Production and Expression of Lovastatin Biosynthetic Genes in Aspergillus terreus via LaeA Regulation. APPL BIOCHEM MICRO+ 2019. [DOI: 10.1134/s0003683819020170] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Cairns TC, Zheng X, Zheng P, Sun J, Meyer V. Moulding the mould: understanding and reprogramming filamentous fungal growth and morphogenesis for next generation cell factories. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:77. [PMID: 30988699 PMCID: PMC6446404 DOI: 10.1186/s13068-019-1400-4] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 03/09/2019] [Indexed: 05/21/2023]
Abstract
Filamentous fungi are harnessed as cell factories for the production of a diverse range of organic acids, proteins, and secondary metabolites. Growth and morphology have critical implications for product titres in both submerged and solid-state fermentations. Recent advances in systems-level understanding of the filamentous lifestyle and development of sophisticated synthetic biological tools for controlled manipulation of fungal genomes now allow rational strain development programs based on data-driven decision making. In this review, we focus on Aspergillus spp. and other industrially utilised fungi to summarise recent insights into the multifaceted and dynamic relationship between filamentous growth and product titres from genetic, metabolic, modelling, subcellular, macromorphological and process engineering perspectives. Current progress and knowledge gaps with regard to mechanistic understanding of product secretion and export from the fungal cell are discussed. We highlight possible strategies for unlocking lead genes for rational strain optimizations based on omics data, and discuss how targeted genetic manipulation of these candidates can be used to optimise fungal morphology for improved performance. Additionally, fungal signalling cascades are introduced as critical processes that can be genetically targeted to control growth and morphology during biotechnological applications. Finally, we review progress in the field of synthetic biology towards chassis cells and minimal genomes, which will eventually enable highly programmable filamentous growth and diversified production capabilities. Ultimately, these advances will not only expand the fungal biotechnology portfolio but will also significantly contribute to a sustainable bio-economy.
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Affiliation(s)
- Timothy C. Cairns
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
| | - Xiaomei Zheng
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
| | - Ping Zheng
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
| | - Jibin Sun
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
| | - Vera Meyer
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- Department of Applied and Molecular Microbiology, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany
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Karaffa L, Kubicek CP. Citric acid and itaconic acid accumulation: variations of the same story? Appl Microbiol Biotechnol 2019; 103:2889-2902. [PMID: 30758523 PMCID: PMC6447509 DOI: 10.1007/s00253-018-09607-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 12/28/2018] [Accepted: 12/28/2018] [Indexed: 01/15/2023]
Abstract
Citric acid production by Aspergillus niger and itaconic acid production by Aspergillus terreus are two major examples of technical scale fungal fermentations based on metabolic overflow of primary metabolism. Both organic acids are formed by the same metabolic pathway, but whereas citric acid is the end product in A. niger, A. terreus performs two additional enzymatic steps leading to itaconic acid. Despite of this high similarity, the optimization of the production process and the mechanism and regulation of overflow of these two acids has mostly been investigated independently, thereby ignoring respective knowledge from the other. In this review, we will highlight where the similarities and the real differences of these two processes occur, which involves various aspects of medium composition, metabolic regulation and compartmentation, transcriptional regulation, and gene evolution. These comparative data may facilitate further investigations of citric acid and itaconic acid accumulation and may contribute to improvements in their industrial production.
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Affiliation(s)
- Levente Karaffa
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen, H-4032, Hungary.
| | - Christian P Kubicek
- Institute of Chemical, Environmental & Bioscience Engineering, TU Wien, Getreidemarkt 9, 1060, Vienna, Austria.,, 1100, Vienna, Austria
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Hu W, Li WJ, Yang HQ, Chen JH. Current strategies and future prospects for enhancing microbial production of citric acid. Appl Microbiol Biotechnol 2018; 103:201-209. [PMID: 30421107 DOI: 10.1007/s00253-018-9491-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 10/27/2018] [Indexed: 10/27/2022]
Abstract
Aspergillus niger and Yarrowia lipolytica are highly important in citric acid (CA) production. To further minimize the cost of CA bio-production using A. niger and Y. lipolytica, some strategies (e.g., metabolic engineering, efficient mutagenesis, and optimal fermentation strategies) were developed to enhance CA production and low-cost carbon sources were also utilized to decrease CA bio-production cost. In this review, we summarize the recent significant progresses in CA bio-production, including metabolic engineering, efficient mutagenesis and screening methods, optimal fermentation strategies, and use of low-cost carbon sources, and future prospects in this field are also discussed, which could help in the development of CA production industry.
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Affiliation(s)
- Wei Hu
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou, 730000, Gansu, China
| | - Wen-Jian Li
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou, 730000, Gansu, China
| | - Hai-Quan Yang
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, Jiangsu, China.
| | - Ji-Hong Chen
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou, 730000, Gansu, China.
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Frisvad JC, Møller LLH, Larsen TO, Kumar R, Arnau J. Safety of the fungal workhorses of industrial biotechnology: update on the mycotoxin and secondary metabolite potential of Aspergillus niger, Aspergillus oryzae, and Trichoderma reesei. Appl Microbiol Biotechnol 2018; 102:9481-9515. [PMID: 30293194 PMCID: PMC6208954 DOI: 10.1007/s00253-018-9354-1] [Citation(s) in RCA: 194] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 08/28/2018] [Accepted: 08/29/2018] [Indexed: 12/11/2022]
Abstract
This review presents an update on the current knowledge of the secondary metabolite potential of the major fungal species used in industrial biotechnology, i.e., Aspergillus niger, Aspergillus oryzae, and Trichoderma reesei. These species have a long history of safe use for enzyme production. Like most microorganisms that exist in a challenging environment in nature, these fungi can produce a large variety and number of secondary metabolites. Many of these compounds present several properties that make them attractive for different industrial and medical applications. A description of all known secondary metabolites produced by these species is presented here. Mycotoxins are a very limited group of secondary metabolites that can be produced by fungi and that pose health hazards in humans and other vertebrates when ingested in small amounts. Some mycotoxins are species-specific. Here, we present scientific basis for (1) the definition of mycotoxins including an update on their toxicity and (2) the clarity on misclassification of species and their mycotoxin potential reported in literature, e.g., A. oryzae has been wrongly reported as an aflatoxin producer, due to misclassification of Aspergillus flavus strains. It is therefore of paramount importance to accurately describe the mycotoxins that can potentially be produced by a fungal species that is to be used as a production organism and to ensure that production strains are not capable of producing mycotoxins during enzyme production. This review is intended as a reference paper for authorities, companies, and researchers dealing with secondary metabolite assessment, risk evaluation for food or feed enzyme production, or considerations on the use of these species as production hosts.
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Affiliation(s)
- Jens C Frisvad
- Department of Biotechnology and Biomedicine (DTU Bioengineering), Technical University of Denmark, Søltofts Plads, B. 221, 2800, Kongens Lyngby, Denmark.
| | - Lars L H Møller
- Department of Product Safety, Novozymes A/S, Krogshoejvej 36, 2880, Bagsvaerd, Denmark
| | - Thomas O Larsen
- Department of Biotechnology and Biomedicine (DTU Bioengineering), Technical University of Denmark, Søltofts Plads, B. 221, 2800, Kongens Lyngby, Denmark
| | - Ravi Kumar
- Department of Genomics and Bioinformatics, Novozymes Inc., 1445 Drew Ave., Davis, CA, 95618, USA
| | - José Arnau
- Department of Fungal Strain Technology and Strain Approval Support, Novozymes A/S, Krogshoejvej 36, 2880, Bagsvaerd, Denmark
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Müller N, Leroch M, Schumacher J, Zimmer D, Könnel A, Klug K, Leisen T, Scheuring D, Sommer F, Mühlhaus T, Schroda M, Hahn M. Investigations on VELVET regulatory mutants confirm the role of host tissue acidification and secretion of proteins in the pathogenesis of Botrytis cinerea. THE NEW PHYTOLOGIST 2018; 219:1062-1074. [PMID: 29790574 DOI: 10.1111/nph.15221] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 04/11/2018] [Indexed: 05/03/2023]
Abstract
The Botrytis cinerea VELVET complex regulates light-dependent development and virulence. The goal of this study was to identify common virulence defects of several VELVET mutants and to reveal their molecular basis. Growth, differentiation, physiology, gene expression and infection of fungal strains were analyzed, and quantitative comparisons of in planta transcriptomes and secretomes were performed. VELVET mutants showed reduced release of citric acid, the major acid secreted by the wild-type, whereas no significant role for oxalic acid was observed. Furthermore, a common set of infection-related and secreted proteins was strongly underexpressed in the mutants. Quantitative secretome analysis with 15 N metabolic labeling revealed a correlation of changes in protein and mRNA levels between wild-type and mutants, indicating that transcript levels determine the abundance of secreted proteins. Infection sites kept at low pH partially restored lesion expansion and expression of virulence genes by the mutants. Drastic downregulation of proteases in the mutants was correlated with incomplete degradation of cellular host proteins at the infection site, but no evidence was obtained that aspartyl proteases are required for lesion formation. The B. cinerea VELVET complex controls pathogenic differentiation by regulating organic acid secretion, host tissue acidification, gene expression and protein secretion.
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Affiliation(s)
- Nathalie Müller
- Department of Biology, Plant Pathology, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Michaela Leroch
- Department of Biology, Plant Pathology, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Julia Schumacher
- Institute of Plant Biology and Biotechnology, Westfälische Wilhelms-Universität Münster, Schlossplatz 8, 48143, Münster, Germany
| | - David Zimmer
- Department of Biology, Computational Systems Biology, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Anne Könnel
- Department of Biology, Plant Pathology, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Klaus Klug
- Department of Biology, Plant Pathology, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Thomas Leisen
- Department of Biology, Plant Pathology, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - David Scheuring
- Department of Biology, Plant Pathology, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Frederik Sommer
- Department of Biology, Molecular Biotechnology & Systems Biology, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Timo Mühlhaus
- Department of Biology, Computational Systems Biology, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Michael Schroda
- Department of Biology, Molecular Biotechnology & Systems Biology, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Matthias Hahn
- Department of Biology, Plant Pathology, University of Kaiserslautern, 67663, Kaiserslautern, Germany
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Cairns TC, Nai C, Meyer V. How a fungus shapes biotechnology: 100 years of Aspergillus niger research. Fungal Biol Biotechnol 2018; 5:13. [PMID: 29850025 PMCID: PMC5966904 DOI: 10.1186/s40694-018-0054-5] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 04/12/2018] [Indexed: 12/20/2022] Open
Abstract
In 1917, a food chemist named James Currie made a promising discovery: any strain of the filamentous mould Aspergillus niger would produce high concentrations of citric acid when grown in sugar medium. This tricarboxylic acid, which we now know is an intermediate of the Krebs cycle, had previously been extracted from citrus fruits for applications in food and beverage production. Two years after Currie’s discovery, industrial-level production using A. niger began, the biochemical fermentation industry started to flourish, and industrial biotechnology was born. A century later, citric acid production using this mould is a multi-billion dollar industry, with A. niger additionally producing a diverse range of proteins, enzymes and secondary metabolites. In this review, we assess main developments in the field of A. niger biology over the last 100 years and highlight scientific breakthroughs and discoveries which were influential for both basic and applied fungal research in and outside the A. niger community. We give special focus to two developments of the last decade: systems biology and genome editing. We also summarize the current international A. niger research community, and end by speculating on the future of fundamental research on this fascinating fungus and its exploitation in industrial biotechnology.
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Affiliation(s)
- Timothy C Cairns
- Department of Applied and Molecular Microbiology, Institute of Biotechnology, Technische Universität Berlin, Gustav-Meyer-Allee 25, 13355 Berlin, Germany
| | - Corrado Nai
- Department of Applied and Molecular Microbiology, Institute of Biotechnology, Technische Universität Berlin, Gustav-Meyer-Allee 25, 13355 Berlin, Germany
| | - Vera Meyer
- Department of Applied and Molecular Microbiology, Institute of Biotechnology, Technische Universität Berlin, Gustav-Meyer-Allee 25, 13355 Berlin, Germany
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42
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Arentshorst M, Ram AFJ. Parasexual Crossings for Bulk Segregant Analysis in Aspergillus niger to Facilitate Mutant Identification Via Whole Genome Sequencing. Methods Mol Biol 2018; 1775:277-287. [PMID: 29876825 DOI: 10.1007/978-1-4939-7804-5_22] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The industrially important fungus Aspergillus niger is known to reproduce only asexually. The parasexual cycle of fungi can be used for crossing two different strains to produce segregants or progeny with combined mutations even in fungi without a known sexual cycle. In A. niger, the parasexual cycle has been extensively used to establish linkage groups and to generate genetic maps. With the advent of whole genome sequencing, the parasexual cycle has received renewed attention as a method to create segregants for bulk segregant analysis. Bulk segregant analysis is a genetic technique used to link and ultimately identify the mutation associated with a particular phenotype. In this chapter we describe the procedure for setting up parasexual crossings in A. niger. The segregants obtained with this method can be used in combination with next-generation sequencing to map mutations in the organism.
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Affiliation(s)
- Mark Arentshorst
- Molecular Microbiology and Biotechnology, Institute of Biology Leiden, Leiden University, Leiden, The Netherlands
| | - Arthur F J Ram
- Molecular Microbiology and Biotechnology, Institute of Biology Leiden, Leiden University, Leiden, The Netherlands.
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43
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Wang B, Lv Y, Li X, Lin Y, Deng H, Pan L. Profiling of secondary metabolite gene clusters regulated by LaeA in Aspergillus niger FGSC A1279 based on genome sequencing and transcriptome analysis. Res Microbiol 2017; 169:67-77. [PMID: 29054463 DOI: 10.1016/j.resmic.2017.10.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 10/07/2017] [Accepted: 10/11/2017] [Indexed: 01/31/2023]
Abstract
The global regulator LaeA controls the production of many fungal secondary metabolites, possibly via chromatin remodeling. Here we aimed to survey the secondary metabolite profile regulated by LaeA in Aspergillus niger FGSC A1279 by genome sequencing and comparative transcriptomics between the laeA deletion (ΔlaeA) and overexpressing (OE-laeA) mutants. Genome sequencing revealed four putative polyketide synthase genes specific to FGSC A1279, suggesting that the corresponding polyketide compounds might be unique to FGSC A1279. RNA-seq data revealed 281 putative secondary metabolite genes upregulated in the OE-laeA mutants, including 22 secondary metabolite backbone genes. LC-MS chemical profiling illustrated that many secondary metabolites were produced in OE-laeA mutants compared to wild type and ΔlaeA mutants, providing potential resources for drug discovery. KEGG analysis annotated 16 secondary metabolite clusters putatively linked to metabolic pathways. Furthermore, 34 of 61 Zn2Cys6 transcription factors located in secondary metabolite clusters were differentially expressed between ΔlaeA and OE-laeA mutants. Three secondary metabolite clusters (cluster 18, 30 and 33) containing Zn2Cys6 transcription factors that were upregulated in OE-laeA mutants were putatively linked to KEGG pathways, suggesting that Zn2Cys6 transcription factors might play an important role in synthesizing secondary metabolites regulated by LaeA. Taken together, LaeA dramatically influences the secondary metabolite profile in FGSC A1279.
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Affiliation(s)
- Bin Wang
- School of Biology and Biological Engineering, South China University of Technology, No. 382 Waihuan East Rd, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China; Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, China.
| | - Yangyong Lv
- School of Biology and Biological Engineering, South China University of Technology, No. 382 Waihuan East Rd, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China.
| | - Xuejie Li
- School of Biology and Biological Engineering, South China University of Technology, No. 382 Waihuan East Rd, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China.
| | - Yiying Lin
- School of Biology and Biological Engineering, South China University of Technology, No. 382 Waihuan East Rd, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China.
| | - Hai Deng
- School of Biology and Biological Engineering, South China University of Technology, No. 382 Waihuan East Rd, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China; Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland, UK.
| | - Li Pan
- School of Biology and Biological Engineering, South China University of Technology, No. 382 Waihuan East Rd, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China; Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, China.
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The FlbA-regulated predicted transcription factor Fum21 of Aspergillus niger is involved in fumonisin production. Antonie van Leeuwenhoek 2017; 111:311-322. [PMID: 28965153 PMCID: PMC5816093 DOI: 10.1007/s10482-017-0952-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 09/25/2017] [Indexed: 12/19/2022]
Abstract
Aspergillus niger secretes proteins throughout the colony except for the zone that forms asexual spores called conidia. Inactivation of flbA that encodes a regulator of G-protein signaling results in colonies that are unable to reproduce asexually and that secrete proteins throughout the mycelium. In addition, the ΔflbA strain shows cell lysis and has thinner cell walls. Expression analysis showed that 38 predicted transcription factor genes are differentially expressed in strain ΔflbA. Here, the most down-regulated predicted transcription factor gene, called fum21, was inactivated. Growth, conidiation, and protein secretion were not affected in strain Δfum21. Whole genome expression analysis revealed that 63 and 11 genes were down- and up-regulated in Δfum21, respectively, when compared to the wild-type strain. Notably, 24 genes predicted to be involved in secondary metabolism were down-regulated in Δfum21, including 10 out of 12 genes of the fumonisin cluster. This was accompanied by absence of fumonisin production in the deletion strain and a 25% reduction in production of pyranonigrin A. Together, these results link FlbA-mediated sporulation-inhibited secretion with mycotoxin production.
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Pfannenstiel BT, Zhao X, Wortman J, Wiemann P, Throckmorton K, Spraker JE, Soukup AA, Luo X, Lindner DL, Lim FY, Knox BP, Haas B, Fischer GJ, Choera T, Butchko RAE, Bok JW, Affeldt KJ, Keller NP, Palmer JM. Revitalization of a Forward Genetic Screen Identifies Three New Regulators of Fungal Secondary Metabolism in the Genus Aspergillus. mBio 2017; 8:e01246-17. [PMID: 28874473 PMCID: PMC5587912 DOI: 10.1128/mbio.01246-17] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 08/08/2017] [Indexed: 11/24/2022] Open
Abstract
The study of aflatoxin in Aspergillus spp. has garnered the attention of many researchers due to aflatoxin's carcinogenic properties and frequency as a food and feed contaminant. Significant progress has been made by utilizing the model organism Aspergillus nidulans to characterize the regulation of sterigmatocystin (ST), the penultimate precursor of aflatoxin. A previous forward genetic screen identified 23 A. nidulans mutants involved in regulating ST production. Six mutants were characterized from this screen using classical mapping (five mutations in mcsA) and complementation with a cosmid library (one mutation in laeA). The remaining mutants were backcrossed and sequenced using Illumina and Ion Torrent sequencing platforms. All but one mutant contained one or more sequence variants in predicted open reading frames. Deletion of these genes resulted in identification of mutant alleles responsible for the loss of ST production in 12 of the 17 remaining mutants. Eight of these mutations were in genes already known to affect ST synthesis (laeA, mcsA, fluG, and stcA), while the remaining four mutations (in laeB, sntB, and hamI) were in previously uncharacterized genes not known to be involved in ST production. Deletion of laeB, sntB, and hamI in A. flavus results in loss of aflatoxin production, confirming that these regulators are conserved in the aflatoxigenic aspergilli. This report highlights the multifaceted regulatory mechanisms governing secondary metabolism in Aspergillus Additionally, these data contribute to the increasing number of studies showing that forward genetic screens of fungi coupled with whole-genome resequencing is a robust and cost-effective technique.IMPORTANCE In a postgenomic world, reverse genetic approaches have displaced their forward genetic counterparts. The techniques used in forward genetics to identify loci of interest were typically very cumbersome and time-consuming, relying on Mendelian traits in model organisms. The current work was pursued not only to identify alleles involved in regulation of secondary metabolism but also to demonstrate a return to forward genetics to track phenotypes and to discover genetic pathways that could not be predicted through a reverse genetics approach. While identification of mutant alleles from whole-genome sequencing has been done before, here we illustrate the possibility of coupling this strategy with a genetic screen to identify multiple alleles of interest. Sequencing of classically derived mutants revealed several uncharacterized genes, which represent novel pathways to regulate and control the biosynthesis of sterigmatocystin and of aflatoxin, a societally and medically important mycotoxin.
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Affiliation(s)
| | - Xixi Zhao
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Jennifer Wortman
- Genome Sequencing and Analysis Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Philipp Wiemann
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Kurt Throckmorton
- Department of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Joseph E Spraker
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Alexandra A Soukup
- Department of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Xingyu Luo
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Daniel L Lindner
- Center for Forest Mycology Research, Northern Research Station, U.S. Forest Service, Madison, Wisconsin, USA
| | - Fang Yun Lim
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Benjamin P Knox
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Brian Haas
- Genome Sequencing and Analysis Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Gregory J Fischer
- Department of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Tsokyi Choera
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Robert A E Butchko
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, USA
| | - Jin-Woo Bok
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Katharyn J Affeldt
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jonathan M Palmer
- Center for Forest Mycology Research, Northern Research Station, U.S. Forest Service, Madison, Wisconsin, USA
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Key role of LaeA and velvet complex proteins on expression of β-lactam and PR-toxin genes in Penicillium chrysogenum: cross-talk regulation of secondary metabolite pathways. ACTA ACUST UNITED AC 2017; 44:525-535. [DOI: 10.1007/s10295-016-1830-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 08/15/2016] [Indexed: 01/11/2023]
Abstract
Abstract
Penicillium chrysogenum is an excellent model fungus to study the molecular mechanisms of control of expression of secondary metabolite genes. A key global regulator of the biosynthesis of secondary metabolites is the LaeA protein that interacts with other components of the velvet complex (VelA, VelB, VelC, VosA). These components interact with LaeA and regulate expression of penicillin and PR-toxin biosynthetic genes in P. chrysogenum. Both LaeA and VelA are positive regulators of the penicillin and PR-toxin biosynthesis, whereas VelB acts as antagonist of the effect of LaeA and VelA. Silencing or deletion of the laeA gene has a strong negative effect on penicillin biosynthesis and overexpression of laeA increases penicillin production. Expression of the laeA gene is enhanced by the P. chrysogenum autoinducers 1,3 diaminopropane and spermidine. The PR-toxin gene cluster is very poorly expressed in P. chrysogenum under penicillin-production conditions (i.e. it is a near-silent gene cluster). Interestingly, the downregulation of expression of the PR-toxin gene cluster in the high producing strain P. chrysogenum DS17690 was associated with mutations in both the laeA and velA genes. Analysis of the laeA and velA encoding genes in this high penicillin producing strain revealed that both laeA and velA acquired important mutations during the strain improvement programs thus altering the ratio of different secondary metabolites (e.g. pigments, PR-toxin) synthesized in the high penicillin producing mutants when compared to the parental wild type strain. Cross-talk of different secondary metabolite pathways has also been found in various Penicillium spp.: P. chrysogenum mutants lacking the penicillin gene cluster produce increasing amounts of PR-toxin, and mutants of P. roqueforti silenced in the PR-toxin genes produce large amounts of mycophenolic acid. The LaeA-velvet complex mediated regulation and the pathway cross-talk phenomenon has great relevance for improving the production of novel secondary metabolites, particularly of those secondary metabolites which are produced in trace amounts encoded by silent or near-silent gene clusters.
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McCluskey K, Baker SE. Diverse data supports the transition of filamentous fungal model organisms into the post-genomics era. Mycology 2017; 8:67-83. [PMID: 30123633 PMCID: PMC6059044 DOI: 10.1080/21501203.2017.1281849] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 01/10/2017] [Indexed: 01/14/2023] Open
Abstract
Filamentous fungi have been important as model organisms since the beginning of modern biological inquiry and have benefitted from open data since the earliest genetic maps were shared. From early origins in simple Mendelian genetics of mating types, parasexual genetics of colony colour, and the foundational demonstration of the segregation of a nutritional requirement, the contribution of research systems utilising filamentous fungi has spanned the biochemical genetics era, through the molecular genetics era, and now are at the very foundation of diverse omics approaches to research and development. Fungal model organisms have come from most major taxonomic groups although Ascomycete filamentous fungi have seen the most major sustained effort. In addition to the published material about filamentous fungi, shared molecular tools have found application in every area of fungal biology. Similarly, shared data has contributed to the success of model systems. The scale of data supporting research with filamentous fungi has grown by 10 to 12 orders of magnitude. From genetic to molecular maps, expression databases, and finally genome resources, the open and collaborative nature of the research communities has assured that the rising tide of data has lifted all of the research systems together.
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Affiliation(s)
- Kevin McCluskey
- Department of Plant Pathology, Kansas State University, Manhattan, KS, USA
| | - Scott E. Baker
- Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory, Richland, WA, USA
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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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Benocci T, Aguilar-Pontes MV, Zhou M, Seiboth B, de Vries RP. Regulators of plant biomass degradation in ascomycetous fungi. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:152. [PMID: 28616076 PMCID: PMC5468973 DOI: 10.1186/s13068-017-0841-x] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 06/06/2017] [Indexed: 05/05/2023]
Abstract
Fungi play a major role in the global carbon cycle because of their ability to utilize plant biomass (polysaccharides, proteins, and lignin) as carbon source. Due to the complexity and heterogenic composition of plant biomass, fungi need to produce a broad range of degrading enzymes, matching the composition of (part of) the prevalent substrate. This process is dependent on a network of regulators that not only control the extracellular enzymes that degrade the biomass, but also the metabolic pathways needed to metabolize the resulting monomers. This review will summarize the current knowledge on regulation of plant biomass utilization in fungi and compare the differences between fungal species, focusing in particular on the presence or absence of the regulators involved in this process.
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Affiliation(s)
- Tiziano Benocci
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Maria Victoria Aguilar-Pontes
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Miaomiao Zhou
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Bernhard Seiboth
- Research Area Biochemical Technology, Institute of Chemical and Biological Engineering, TU Wien, 1060 Vienna, Austria
| | - Ronald P. de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
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Meyer V, Andersen MR, Brakhage AA, Braus GH, Caddick MX, Cairns TC, de Vries RP, Haarmann T, Hansen K, Hertz-Fowler C, Krappmann S, Mortensen UH, Peñalva MA, Ram AFJ, Head RM. Current challenges of research on filamentous fungi in relation to human welfare and a sustainable bio-economy: a white paper. Fungal Biol Biotechnol 2016; 3:6. [PMID: 28955465 PMCID: PMC5611618 DOI: 10.1186/s40694-016-0024-8] [Citation(s) in RCA: 155] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 08/10/2016] [Indexed: 12/15/2022] Open
Abstract
The EUROFUNG network is a virtual centre of multidisciplinary expertise in the field of fungal biotechnology. The first academic-industry Think Tank was hosted by EUROFUNG to summarise the state of the art and future challenges in fungal biology and biotechnology in the coming decade. Currently, fungal cell factories are important for bulk manufacturing of organic acids, proteins, enzymes, secondary metabolites and active pharmaceutical ingredients in white and red biotechnology. In contrast, fungal pathogens of humans kill more people than malaria or tuberculosis. Fungi are significantly impacting on global food security, damaging global crop production, causing disease in domesticated animals, and spoiling an estimated 10 % of harvested crops. A number of challenges now need to be addressed to improve our strategies to control fungal pathogenicity and to optimise the use of fungi as sources for novel compounds and as cell factories for large scale manufacture of bio-based products. This white paper reports on the discussions of the Think Tank meeting and the suggestions made for moving fungal bio(techno)logy forward.
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Affiliation(s)
- Vera Meyer
- Department of Applied and Molecular Microbiology, Institute of Biotechnology, Berlin University of Technology, Gustav-Meyer-Allee 25, 13355 Berlin, Germany
| | - Mikael R. Andersen
- Department of Systems Biology, Technical University of Denmark, Building 223, 2800 Lyngby, Denmark
| | - Axel A. Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany
- Department of Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Gerhard H. Braus
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics, Georg-August-Universität Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
| | - Mark X. Caddick
- Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB UK
| | - Timothy C. Cairns
- Department of Applied and Molecular Microbiology, Institute of Biotechnology, Berlin University of Technology, Gustav-Meyer-Allee 25, 13355 Berlin, Germany
| | - Ronald P. de Vries
- Fungal Physiology, CBS-KNAW Fungal Biodiversity Centre and Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | | | - Kim Hansen
- Biotechnology Research, Production Strain Technology, Novozymes A/S, Krogshoejvej 36, 2880 Bagsvaerd, Denmark
| | - Christiane Hertz-Fowler
- Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB UK
| | - Sven Krappmann
- Mikrobiologisches Institut – Klinische Mikrobiologie, Immunologie und Hygiene, Friedrich-Alexander University Erlangen-Nürnberg and University Hospital Erlangen, Wasserturmstr. 3/5, 91054 Erlangen, Germany
| | - Uffe H. Mortensen
- Department of Systems Biology, Technical University of Denmark, Building 223, 2800 Lyngby, Denmark
| | - Miguel A. Peñalva
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Arthur F. J. Ram
- Molecular Microbiology and Biotechnology, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
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