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Wang G, Li Y, Yang B, Li E, Wu W, Si P, Xing F. AwAreA Regulates Morphological Development, Ochratoxin A Production, and Fungal Pathogenicity of Food Spoilage Fungus Aspergillus westerdijkiae Revealed by an Efficient Gene Targeting System. Front Microbiol 2022; 13:857726. [PMID: 35432249 PMCID: PMC9009206 DOI: 10.3389/fmicb.2022.857726] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 02/07/2022] [Indexed: 11/13/2022] Open
Abstract
Aspergillus westerdijkiae, the producer of ochratoxin A (OTA), which is of worldwide concern, is an import fungal species in agriculture, food, and industry. Here, we got the uridine auxotrophic mutant of A. westerdijkiae by deleting AwpyrG. The ΔAwpyrG could be used for bio-transformation with exogenous AfpyrG expression cassette as a selection marker. In order to enhance the efficiency of gene targeting, Awku70 and Awlig4 were homologously deleted from ΔAwpyrG. The efficiencies of homologous replacement for ΔAwku70 and ΔAwlig4 were 95.7 and 87.0% in the deletion of AwAreA, respectively, demonstrating a drastic increase from 4.3% of the wild type (WT) strain. Furthermore, the function of AwAreA was identified with AwAreA deletion mutant and the control strain ΔAwku70. AwAreA regulated the growth and conidiation of A. westerdijkiae in response to nitrogen sources. The concentration of OTA for ΔAwku70 was in the range of 19.4 to 186.9 ng/cm2 on all kinds of nitrogen sources. The OTA production influenced by the deletion of AwAreA was different based on nitrogen sources. Pathogenicity assays on pears, grapes, salted meat, and cheese showed that AwAreA acted as a negative regulator in the infection of food substrates. Therefore, the genetic methods and engineered strains enable us to substantially expand the use of A. westerdijkiae, one of more than twenty OTA-producing fungi, in the study of mycotoxin biosynthesis and regulation, and consequently to aim at providing new ways for controlling this pathogen.
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Affiliation(s)
- Gang Wang
- Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yujie Li
- Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Bolei Yang
- Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Erfeng Li
- Horticulture and Landscape College, Tianjin Agricultural University, Tianjin, China
| | - Wenqing Wu
- Horticulture and Landscape College, Tianjin Agricultural University, Tianjin, China
| | - Peidong Si
- Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Fuguo Xing
- Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
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Zhang J, Yin WB. Characterisation of two unique sesquiterpenoids from Trichoderma hypoxylon. Mycology 2022; 13:32-38. [PMID: 35186411 PMCID: PMC8856097 DOI: 10.1080/21501203.2021.1964630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Two new sesquiterpenoids, 1–2, together with three known compounds, were isolated from Trichoderma hypoxylon. Among the known compounds, compound 4 was isolated as naturally occurring compound for the first time. The structures of these new compounds were characterized by HR-ESI-MS and spectroscopic methods including 1D and 2D NMR. The absolute configurations of 1–2 were assigned by electronic circular dichroism (ECD) calculations.
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Affiliation(s)
- Jinyu Zhang
- State Key Laboratory Of Mycology, Institute Of Microbiology, Chinese Academy Of Sciences, Beijing, Republic of China.,University Of Chinese Academy Of Sciences, Beijing, Republic of China
| | - Wen-Bing Yin
- State Key Laboratory Of Mycology, Institute Of Microbiology, Chinese Academy Of Sciences, Beijing, Republic of China.,University Of Chinese Academy Of Sciences, Beijing, Republic of China
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Tomico-Cuenca I, Mach RL, Mach-Aigner AR, Derntl C. An overview on current molecular tools for heterologous gene expression in Trichoderma. Fungal Biol Biotechnol 2021; 8:11. [PMID: 34702369 PMCID: PMC8549263 DOI: 10.1186/s40694-021-00119-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 10/16/2021] [Indexed: 11/10/2022] Open
Abstract
Fungi of the genus Trichoderma are routinely used as biocontrol agents and for the production of industrial enzymes. Trichoderma spp. are interesting hosts for heterologous gene expression because their saprotrophic and mycoparasitic lifestyles enable them to thrive on a large number of nutrient sources and some members of this genus are generally recognized as safe (GRAS status). In this review, we summarize and discuss several aspects involved in heterologous gene expression in Trichoderma, including transformation methods, genome editing strategies, native and synthetic expression systems and implications of protein secretion. This review focuses on the industrial workhorse Trichoderma reesei because this fungus is the best-studied member of this genus for protein expression and secretion. However, the discussed strategies and tools can be expected to be transferable to other Trichoderma species.
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Affiliation(s)
- Irene Tomico-Cuenca
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Strasse 1a, 1060, Wien, Austria
| | - Robert L Mach
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Strasse 1a, 1060, Wien, Austria
| | - Astrid R Mach-Aigner
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Strasse 1a, 1060, Wien, Austria
| | - Christian Derntl
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Strasse 1a, 1060, Wien, Austria.
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Fan C, Zhang W, Su X, Ji W, Luo H, Zhang Y, Liu B, Yao B, Huang H, Xu X. CRISPR/Cas9-mediated genome editing directed by a 5S rRNA-tRNA Gly hybrid promoter in the thermophilic filamentous fungus Humicola insolens. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:206. [PMID: 34688310 PMCID: PMC8542335 DOI: 10.1186/s13068-021-02057-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 10/13/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Humicola insolens is a filamentous fungus with high potential of producing neutral and heat- and alkali-resistant cellulase. However, the genetic engineering tools, particularly the genome-editing tool, are scarce, hindering the study of cellulase expression regulation in this organism. RESULTS Herein, a CRISPR/Cas9 genome-editing system was established in H. insolens based on a hybrid 5S rRNA-tRNAGly promoter. This system is superior to the HDV (hepatitis delta virus) system in genome editing, allowing highly efficient single gene destruction in H. insolens with rates of deletion up to 84.1% (37/44). With this system, a putative pigment synthesis gene pks and the transcription factor xyr1 gene were disrupted with high efficiency. Moreover, the extracellular protein concentration and cellulase activity largely decreased when xyr1 was deleted, demonstrating for the first time that Xyr1 plays an important role in cellulase expression regulation. CONCLUSIONS The established CRISPR/Cas9 system is a powerful genetic operation tool for H. insolens, which will accelerate studies on the regulation mechanism of cellulase expression and engineering of H. insolens for higher cellulase production.
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Affiliation(s)
- Chao Fan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Wei Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Xiaoyun Su
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China
| | - Wangli Ji
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Huiying Luo
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China
| | - Yuhong Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Bo Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Bin Yao
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China
| | - Huoqing Huang
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China.
| | - Xinxin Xu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China.
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Xu X, Huang R, Yin WB. An Optimized and Efficient CRISPR/Cas9 System for the Endophytic Fungus Pestalotiopsis fici. J Fungi (Basel) 2021; 7:809. [PMID: 34682231 PMCID: PMC8539907 DOI: 10.3390/jof7100809] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 09/20/2021] [Accepted: 09/21/2021] [Indexed: 11/17/2022] Open
Abstract
Endophytic fungi are emerging as attractive producers of natural products with diverse bioactivities and novel structures. However, difficulties in the genetic manipulation of endophytic fungi limit the search of novel secondary metabolites. In this study, we improved the polyethylene glycol (PEG)-mediated protoplast transformation method by introducing the CRISPR/Cas9 system into endophytic fungus Pestalotiopsis fici. Using this approach, we performed genome editing such as site-specific gene insertion, dual-locus mutations, and long DNA fragment deletions in P. fici efficiently. The average efficiency for site-specific gene insertion and two-site gene editing was up to 48.0% and 44.4%, respectively. In addition, the genetic manipulation time with long DNA fragment (5-10 kb) deletion was greatly shortened to one week in comparison with traditional methods such as Agrobacterium tumefaciens-mediated transformation (ATMT). Taken together, the development of the CRISPR/Cas9 system in the endophytic fungus will accelerate the discovery of novel natural products and further biological study.
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Affiliation(s)
- Xinran Xu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (X.X.); (R.H.)
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Runye Huang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (X.X.); (R.H.)
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wen-Bing Yin
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (X.X.); (R.H.)
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
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Discovery and genetic identification of amphiphilic coprogen siderophores from Trichoderm hypoxylon. Appl Microbiol Biotechnol 2021; 105:2831-2839. [PMID: 33758985 DOI: 10.1007/s00253-021-11245-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/09/2021] [Accepted: 03/16/2021] [Indexed: 12/18/2022]
Abstract
Siderophores are small molecular iron chelators and participate in the multiple cellular processes in fungi. In this study, we discovered and identified five amphiphilic coprogen siderophores including three new natural products according to LC-MS-guided separation strategy from Trichoderm hypoxylon. The structures of three new coprogens were elucidated by NMR spectroscopy, and high-resolution (HR)-ESI-MS analysis. Genetic deletions of dfcA and dfcB abolished the production of compounds 1-5 that implied their involvement in the biosynthesis of coprogens. Interestingly, cultivations of ΔdfcA and ΔdfcB mutants with pathogenic fungi Fusarium oxysporum and Mucor corcinelloides showed the weaker inhibitions in comparison to wild type that demonstrated coprogen's role in combating the pathogenic fungi. Our study not only enriched the diversities of siderophores but also provided an approach for finding the rare amphiphilic coprogen siderophores in fungi. Furthermore, this work provided a basis for investigation on the biosynthesis of fungal amphiphilic siderophores and their ecological roles in nature. KEY POINTS: • A series of amphiphilic coprogens were found. • The gene cluster of amphiphilic coprogens and ecological roles were elucidated.
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Liu H, Fan J, Zhang P, Hu Y, Liu X, Li SM, Yin WB. New insights into the disulfide bond formation enzymes in epidithiodiketopiperazine alkaloids. Chem Sci 2021; 12:4132-4138. [PMID: 34163685 PMCID: PMC8179532 DOI: 10.1039/d0sc06647h] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Epidithiodiketopiperazines (ETPs) are a group of bioactive fungal natural products and structurally feature unique transannular disulfide bridges between α, α or α, β carbons. However, no enzyme has yet been demonstrated to catalyse α, β-disulfide bond formation in these molecules. Through genome mining and gene deletion approaches in Trichoderma hypoxylon, we identified a putative biosynthetic gene cluster of pretrichodermamide A (1), which requires a FAD-dependent oxidoreductase, TdaR, for the irregular α, β-disulfide formation in 1 biosynthesis. In vitro assays of TdaR, together with AclT involved in aspirochlorine and GliT involved in gliotoxin biosynthesis, proved that all three enzymes catalyse not only the conversion of red-pretrichodermamide A (4) to α, β-disulfide-containing 1 but also that of red-gliotoxin (5) to α, α-disulfide-containing gliotoxin (6). These results provide new insights into the thiol-disulfide oxidases responsible for the disulfide bond formation in natural products with significant substrate and catalytic promiscuities. A FAD-dependent oxidoreductase TdaR was responsible for α, β-disulfide formation in the biosynthesis of pretrichodermamide A. TdaR, together with its homologs AclT and GliT, catalysed not only α, α- but also α, β-disulfide formation in fungi.![]()
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Affiliation(s)
- Huan Liu
- State Key Laboratory of Mycology, CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences Beijing 100101 P. R. China
| | - Jie Fan
- State Key Laboratory of Mycology, CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences Beijing 100101 P. R. China
| | - Peng Zhang
- State Key Laboratory of Mycology, CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences Beijing 100101 P. R. China
| | - Youcai Hu
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing 100050 P. R. China
| | - Xingzhong Liu
- State Key Laboratory of Mycology, CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences Beijing 100101 P. R. China
| | - Shu-Ming Li
- Institut für Pharmazeutische Biologie und Biotechnologie, Fachbereich Pharmazie, Philipps-Universität Marburg Robert-Koch-Straße 4 Marburg 35037 Germany
| | - Wen-Bing Yin
- State Key Laboratory of Mycology, CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences Beijing 100101 P. R. China .,Savaid Medical School, University of Chinese Academy of Sciences Beijing 100049 P. R. China
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Liu H, Pu YH, Ren JW, Li EW, Guo LX, Yin WB. Genetic dereplication driven discovery of a tricinoloniol acid biosynthetic pathway in Trichoderma hypoxylon. Org Biomol Chem 2020; 18:5344-5348. [PMID: 32638809 DOI: 10.1039/d0ob01202e] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A genetic dereplication approach in combination with differential gene expression led to the discovery of three new sesquiterpenes, tricinoloniol acids (TRAs) A-C (1-3) and the known fusidilactone A (4) from T. hypoxylon. Comparative transcriptomic analysis and targeted deletion identified the biosynthetic route for TRAs. Our results demonstrate an alternative application of the genetic dereplication method for exploring the biosynthesis of cryptic secondary metabolites (SMs), which utilizes the coordinated expression of trichothecene (tri) and tra cluster genes.
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Affiliation(s)
- Huan Liu
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, PR China. and State Key Laboratory of Mycology and CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, PR China
| | - Yu-Han Pu
- Environmental and Resources Institute, Chongqing Technology and Business University, Chongqing 400067, PR China
| | - Jin-Wei Ren
- State Key Laboratory of Mycology and CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, PR China
| | - Er-Wei Li
- State Key Laboratory of Mycology and CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, PR China
| | - Li-Xia Guo
- Environmental and Resources Institute, Chongqing Technology and Business University, Chongqing 400067, PR China
| | - Wen-Bing Yin
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, PR China. and State Key Laboratory of Mycology and CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, PR China
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Calcáneo-Hernández G, Rojas-Espinosa E, Landeros-Jaime F, Cervantes-Chávez JA, Esquivel-Naranjo EU. An efficient transformation system for Trichoderma atroviride using the pyr4 gene as a selectable marker. Braz J Microbiol 2020; 51:1631-1643. [PMID: 32627116 DOI: 10.1007/s42770-020-00329-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 06/25/2020] [Indexed: 10/23/2022] Open
Abstract
The development of an efficient transformation system is essential to enrich the genetic understanding of Trichoderma atroviride. To acquire an additional homologous selectable marker, uracil auxotrophic mutants were generated. First, the pyr4 gene encoding OMP decarboxylase was replaced by the hph marker gene, encoding a hygromycin phosphotransferase. Then, uracil auxotrophs were employed to determine that 5 mM uracil restores their growth and conidia production, and 1 mg ml-1 is the lethal dose of 5-fluoroorotic acid in T. atroviride. Subsequently, uracil auxotrophic strains, free of a drug-selectable marker, were selected by 5-fluoroorotic acid resistance. Two different deletions in pyr4 were mapped in four auxotrophs, encoding a protein with frameshifts at the 310 and 335 amino acids in their COOH-terminal. Six auxotrophs did not have changes in the pyr4 ORF even though a specific cassette to delete the pyr4 was used, suggesting that 5-FOA could have mutagenic activity. The Ura-1 strain was selected as a genetic background to knock out the MAPKK Pbs2, MAPK Tmk3, and the blue light receptors Blr1/Blr2, using a short version of pyr4 as a homologous marker. The ∆tmk3 and ∆pbs2 mutants selected with pyr4 or hph marker were phenotypically identical, highly sensitive to different stressors, and affected in photoconidiation. The ∆blr1 and ∆blr2 mutants were not responsive to light, and complementation of uracil biosynthesis did not interfere in the expression of blu1, grg2, phr1, and env1 genes upregulated by blue light. Overall, uracil metabolism can be used as a tool for genetic manipulation in T. atroviride.
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Affiliation(s)
- Gabriela Calcáneo-Hernández
- Unit for Basic and Applied Microbiology, School of Natural Sciences, Autonomous University of Queretaro, 76140, Queretaro, Mexico
| | - Erick Rojas-Espinosa
- Unit for Basic and Applied Microbiology, School of Natural Sciences, Autonomous University of Queretaro, 76140, Queretaro, Mexico
| | - Fidel Landeros-Jaime
- Unit for Basic and Applied Microbiology, School of Natural Sciences, Autonomous University of Queretaro, 76140, Queretaro, Mexico
| | - José Antonio Cervantes-Chávez
- Unit for Basic and Applied Microbiology, School of Natural Sciences, Autonomous University of Queretaro, 76140, Queretaro, Mexico
| | - Edgardo Ulises Esquivel-Naranjo
- Unit for Basic and Applied Microbiology, School of Natural Sciences, Autonomous University of Queretaro, 76140, Queretaro, Mexico.
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Bioactive Metabolites and Potential Mycotoxins Produced by Cordyceps Fungi: A Review of Safety. Toxins (Basel) 2020; 12:toxins12060410. [PMID: 32575649 PMCID: PMC7354514 DOI: 10.3390/toxins12060410] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 12/19/2022] Open
Abstract
Ascomycete Cordyceps fungi such as C. militaris, C. cicadae, and C. guangdongensis have been mass produced on artificial media either as food supplements or health additives while the byproducts of culture substrates are largely used as animal feed. The safety concerns associated with the daily consumption of Cordyceps fungi or related products are still being debated. On the one hand, the known compounds from these fungi such as adenosine analogs cordycepin and pentostatin have demonstrated different beneficial or pharmaceutical activities but also dose-dependent cytotoxicities, neurological toxicities and or toxicological effects in humans and animals. On the other hand, the possibility of mycotoxin production by Cordyceps fungi has not been completely ruled out. In contrast to a few metabolites identified, an array of biosynthetic gene clusters (BGCs) are encoded in each genome of these fungi with the potential to produce a plethora of as yet unknown secondary metabolites. Conservation analysis of BGCs suggests that mycotoxin analogs of PR-toxin and trichothecenes might be produced by Cordyceps fungi. Future elucidation of the compounds produced by these functionally unknown BGCs, and in-depth assessments of metabolite bioactivity and chemical safety, will not only facilitate the safe use of Cordyceps fungi as human food or alternative medicine, but will also benefit the use of mass production byproducts as animal feed. To corroborate the long record of use as a traditional medicine, future efforts will also benefit the exploration of Cordyceps fungi for pharmaceutical purposes.
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Álvarez-Escribano I, Sasse C, Bok JW, Na H, Amirebrahimi M, Lipzen A, Schackwitz W, Martin J, Barry K, Gutiérrez G, Cea-Sánchez S, Marcos AT, Grigoriev IV, Keller NP, Braus GH, Cánovas D. Genome sequencing of evolved aspergilli populations reveals robust genomes, transversions in A. flavus, and sexual aberrancy in non-homologous end-joining mutants. BMC Biol 2019; 17:88. [PMID: 31711484 PMCID: PMC6844060 DOI: 10.1186/s12915-019-0702-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 09/19/2019] [Indexed: 01/19/2023] Open
Abstract
Background Aspergillus spp. comprises a very diverse group of lower eukaryotes with a high relevance for industrial applications and clinical implications. These multinucleate species are often cultured for many generations in the laboratory, which can unknowingly propagate hidden genetic mutations. To assess the likelihood of such events, we studied the genome stability of aspergilli by using a combination of mutation accumulation (MA) lines and whole genome sequencing. Results We sequenced the whole genomes of 30 asexual and 10 sexual MA lines of three Aspergillus species (A. flavus, A. fumigatus and A. nidulans) and estimated that each MA line accumulated mutations for over 4000 mitoses during asexual cycles. We estimated mutation rates of 4.2 × 10−11 (A. flavus), 1.1 × 10−11 (A. fumigatus) and 4.1 × 10−11 (A. nidulans) per site per mitosis, suggesting that the genomes are very robust. Unexpectedly, we found a very high rate of GC → TA transversions only in A. flavus. In parallel, 30 asexual lines of the non-homologous end-joining (NHEJ) mutants of the three species were also allowed to accumulate mutations for the same number of mitoses. Sequencing of these NHEJ MA lines gave an estimated mutation rate of 5.1 × 10−11 (A. flavus), 2.2 × 10−11 (A. fumigatus) and 4.5 × 10−11 (A. nidulans) per base per mitosis, which is slightly higher than in the wild-type strains and some ~ 5–6 times lower than in the yeasts. Additionally, in A. nidulans, we found a NHEJ-dependent interference of the sexual cycle that is independent of the accumulation of mutations. Conclusions We present for the first time direct counts of the mutation rate of filamentous fungal species and find that Aspergillus genomes are very robust. Deletion of the NHEJ machinery results in a slight increase in the mutation rate, but at a rate we suggest is still safe to use for biotechnology purposes. Unexpectedly, we found GC→TA transversions predominated only in the species A. flavus, which could be generated by the hepatocarcinogen secondary metabolite aflatoxin. Lastly, a strong effect of the NHEJ mutation in self-crossing was observed and an increase in the mutations of the asexual lines was quantified.
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Affiliation(s)
- Isidro Álvarez-Escribano
- Department of Genetics, Faculty of Biology, University of Seville, Seville, Spain.,Present Address: Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas y Universidad de Sevilla, Seville, Spain
| | - Christoph Sasse
- Department of Molecular Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University, Göttingen, Germany
| | - Jin Woo Bok
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - Hyunsoo Na
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
| | | | - Anna Lipzen
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
| | - Wendy Schackwitz
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
| | - Joel Martin
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
| | - Kerrie Barry
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
| | - Gabriel Gutiérrez
- Department of Genetics, Faculty of Biology, University of Seville, Seville, Spain
| | - Sara Cea-Sánchez
- Department of Genetics, Faculty of Biology, University of Seville, Seville, Spain
| | - Ana T Marcos
- Department of Genetics, Faculty of Biology, University of Seville, Seville, Spain.,Present Address: Instituto para el Estudio de la Reproducción Humana (Inebir), Avda de la Cruz Roja 1, 41009, Sevilla, Spain
| | - Igor V Grigoriev
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, USA.,Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA.,Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA
| | - Gerhard H Braus
- Department of Molecular Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University, Göttingen, Germany
| | - David Cánovas
- Department of Genetics, Faculty of Biology, University of Seville, Seville, Spain.
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Chen L, Wu H, Liu H, Li E, Ren J, Wang W, Wang S, Yin WB. Genetic dereplication of Trichoderma hypoxylon reveals two novel polycyclic lactones. Bioorg Chem 2019; 91:103185. [PMID: 31430681 DOI: 10.1016/j.bioorg.2019.103185] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 07/24/2019] [Accepted: 08/04/2019] [Indexed: 01/09/2023]
Abstract
Previous study demonstrated large scale production of trichochecenes which limited the discovery of novel metabolites in Trichoderma hypoxylon. By genetic deletion of trichothecene synthase encoding gene thtri5, we created the dereplication mutant which eliminated the production of trichothecenes. Through chemical isolation, we characterized a couple of rare new polycyclic lactones tricholactones A and B from the thtri5 deletion strain. The structures of these two compounds were well determined by NMR, HR-ESI-MS and IECD analysis.
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Affiliation(s)
- Lin Chen
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Zhengzhou Key Laboratory of Synthetic Biology of Natural Products, Huanghe Science and Technology College, Zhengzhou 450006, China
| | - HongBo Wu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Huan Liu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Erwei Li
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jinwei Ren
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Wenzhao Wang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Shihua Wang
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Wen-Bing Yin
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China.
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