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Seo HW, Wassano NS, Amir Rawa MS, Nickles GR, Damasio A, Keller NP. A Timeline of Biosynthetic Gene Cluster Discovery in Aspergillus fumigatus: From Characterization to Future Perspectives. J Fungi (Basel) 2024; 10:266. [PMID: 38667937 PMCID: PMC11051388 DOI: 10.3390/jof10040266] [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: 03/08/2024] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 04/28/2024] Open
Abstract
In 1999, the first biosynthetic gene cluster (BGC), synthesizing the virulence factor DHN melanin, was characterized in Aspergillus fumigatus. Since then, 19 additional BGCs have been linked to specific secondary metabolites (SMs) in this species. Here, we provide a comprehensive timeline of A. fumigatus BGC discovery and find that initial advances centered around the commonly expressed SMs where chemical structure informed rationale identification of the producing BGC (e.g., gliotoxin, fumigaclavine, fumitremorgin, pseurotin A, helvolic acid, fumiquinazoline). Further advances followed the transcriptional profiling of a ΔlaeA mutant, which aided in the identification of endocrocin, fumagillin, hexadehydroastechrome, trypacidin, and fumisoquin BGCs. These SMs and their precursors are the commonly produced metabolites in most A. fumigatus studies. Characterization of other BGC/SM pairs required additional efforts, such as induction treatments, including co-culture with bacteria (fumicycline/neosartoricin, fumigermin) or growth under copper starvation (fumivaline, fumicicolin). Finally, four BGC/SM pairs were discovered via overexpression technologies, including the use of heterologous hosts (fumicycline/neosartoricin, fumihopaside, sphingofungin, and sartorypyrone). Initial analysis of the two most studied A. fumigatus isolates, Af293 and A1160, suggested that both harbored ca. 34-36 BGCs. However, an examination of 264 available genomes of A. fumigatus shows up to 20 additional BGCs, with some strains showing considerable variations in BGC number and composition. These new BGCs present a new frontier in the future of secondary metabolism characterization in this important species.
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Affiliation(s)
- Hye-Won Seo
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA; (H.-W.S.); (N.S.W.); (M.S.A.R.); (G.R.N.)
| | - Natalia S. Wassano
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA; (H.-W.S.); (N.S.W.); (M.S.A.R.); (G.R.N.)
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), São Paulo 13083-970, Brazil;
| | - Mira Syahfriena Amir Rawa
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA; (H.-W.S.); (N.S.W.); (M.S.A.R.); (G.R.N.)
| | - Grant R. Nickles
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA; (H.-W.S.); (N.S.W.); (M.S.A.R.); (G.R.N.)
| | - André Damasio
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), São Paulo 13083-970, Brazil;
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA; (H.-W.S.); (N.S.W.); (M.S.A.R.); (G.R.N.)
- Department of Plant Pathology, University of Wisconsin, Madison, WI 53706, USA
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2
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Alves de Castro P, Figueiredo Pinzan C, Dos Reis TF, Valero C, Van Rhijn N, Menegatti C, de Freitas Migliorini IL, Bromley M, Fleming AB, Traynor AM, Sarikaya-Bayram Ö, Bayram Ö, Malavazi I, Ebel F, Barbosa JCJ, Fill T, Pupo MT, Goldman GH. Aspergillus fumigatus mitogen-activated protein kinase MpkA is involved in gliotoxin production and self-protection. Nat Commun 2024; 15:33. [PMID: 38167253 PMCID: PMC10762094 DOI: 10.1038/s41467-023-44329-1] [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: 05/22/2023] [Accepted: 12/08/2023] [Indexed: 01/05/2024] Open
Abstract
Aspergillus fumigatus is a saprophytic fungus that can cause a variety of human diseases known as aspergillosis. Mycotoxin gliotoxin (GT) production is important for its virulence and must be tightly regulated to avoid excess production and toxicity to the fungus. GT self-protection by GliT oxidoreductase and GtmA methyltransferase activities is related to the subcellular localization of these enzymes and how GT can be sequestered from the cytoplasm to avoid increased cell damage. Here, we show that GliT:GFP and GtmA:GFP are localized in the cytoplasm and in vacuoles during GT production. The Mitogen-Activated Protein kinase MpkA is essential for GT production and self-protection, interacts physically with GliT and GtmA and it is necessary for their regulation and subsequent presence in the vacuoles. The sensor histidine kinase SlnASln1 is important for modulation of MpkA phosphorylation. Our work emphasizes the importance of MpkA and compartmentalization of cellular events for GT production and self-defense.
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Affiliation(s)
- Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Camila Figueiredo Pinzan
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Thaila Fernanda Dos Reis
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Clara Valero
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Norman Van Rhijn
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Carla Menegatti
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | | | - Michael Bromley
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Alastair B Fleming
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin, Ireland
| | - Aimee M Traynor
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
| | | | - Özgür Bayram
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland.
| | - Iran Malavazi
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil
| | - Frank Ebel
- Institut für Infektionsmedizin und Zoonosen, Medizinische Fakultät, LMU, 80539, München, Germany
| | | | - Taícia Fill
- Instituto de Química, Universidade Estadual de Campinas, Campinas, Brazil
| | - Monica Tallarico Pupo
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Gustavo H Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
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3
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Gopalakrishnan Meena M, Lane MJ, Tannous J, Carrell AA, Abraham PE, Giannone RJ, Ané JM, Keller NP, Labbé JL, Geiger AG, Kainer D, Jacobson DA, Rush TA. A glimpse into the fungal metabolomic abyss: Novel network analysis reveals relationships between exogenous compounds and their outputs. PNAS NEXUS 2023; 2:pgad322. [PMID: 37854706 PMCID: PMC10581544 DOI: 10.1093/pnasnexus/pgad322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 09/20/2023] [Indexed: 10/20/2023]
Abstract
Fungal specialized metabolites are a major source of beneficial compounds that are routinely isolated, characterized, and manufactured as pharmaceuticals, agrochemical agents, and industrial chemicals. The production of these metabolites is encoded by biosynthetic gene clusters that are often silent under standard growth conditions. There are limited resources for characterizing the direct link between abiotic stimuli and metabolite production. Herein, we introduce a network analysis-based, data-driven algorithm comprising two routes to characterize the production of specialized fungal metabolites triggered by different exogenous compounds: the direct route and the auxiliary route. Both routes elucidate the influence of treatments on the production of specialized metabolites from experimental data. The direct route determines known and putative metabolites induced by treatments and provides additional insight over traditional comparison methods. The auxiliary route is specific for discovering unknown analytes, and further identification can be curated through online bioinformatic resources. We validated our algorithm by applying chitooligosaccharides and lipids at two different temperatures to the fungal pathogen Aspergillus fumigatus. After liquid chromatography-mass spectrometry quantification of significantly produced analytes, we used network centrality measures to rank the treatments' ability to elucidate these analytes and confirmed their identity through fragmentation patterns or in silico spiking with commercially available standards. Later, we examined the transcriptional regulation of these metabolites through real-time quantitative polymerase chain reaction. Our data-driven techniques can complement existing metabolomic network analysis by providing an approach to track the influence of any exogenous stimuli on metabolite production. Our experimental-based algorithm can overcome the bottlenecks in elucidating novel fungal compounds used in drug discovery.
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Affiliation(s)
| | - Matthew J Lane
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN 37916, USA
| | - Joanna Tannous
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Alyssa A Carrell
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Paul E Abraham
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Richard J Giannone
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Jean-Michel Ané
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Agronomy, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Nancy P Keller
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Jesse L Labbé
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Now at Tekholding, Salt Lake City, UT 84119, USA
| | - Armin G Geiger
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN 37916, USA
| | - David Kainer
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Now at ARC Centre of Excellence for Plant Success in Nature and Agriculture, University of Queensland, Brisbane, QLD 4072, Australia
| | - Daniel A Jacobson
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Tomás A Rush
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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Xue J, Sun L, Xu H, Gu Y, Lei P. Bacillus atrophaeus NX-12 Utilizes Exosmotic Glycerol from Fusarium oxysporum f. sp. cucumerinum for Fengycin Production. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023. [PMID: 37410693 DOI: 10.1021/acs.jafc.3c01276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
Bacillus strains are widely used as biological control agents to protect plants from fungal pathogens. However, whether Bacillus can exploit fungal pathogens to increase its biocontrol efficacy remains largely unexplored. Here, Bacillus atrophaeus NX-12 showed a high inhibition efficacy against Fusarium oxysporum f. sp. cucumerinum (FOC). The primary extracellular antifungal component of B. atrophaeus NX-12 was identified as fengycin by matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) analysis. NX-12-secreted fengycin not only inhibited the germination of FOC spores but also induced the production of reactive oxygen species (ROS) in FOC cells, leading to oxidative stress and the accumulation of glycerol. Additionally, NX-12-secreted fengycin increased FOC cell wall hydrolase activity, leading to cell splitting and the exosmose of accumulated glycerol. The increased exosmose of glycerol further promoted the production of fengycin. Our results showed that in addition to the direct inhibition of FOC, NX-12 can indirectly strengthen its antagonistic efficacy against the pathogen by exploiting the exosmotic glycerol from FOC.
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Affiliation(s)
- Jian Xue
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China
| | - Liang Sun
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China
| | - Hong Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China
| | - Yian Gu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China
| | - Peng Lei
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China
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5
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Tannous J, Cosetta CM, Drott MT, Rush TA, Abraham PE, Giannone RJ, Keller NP, Wolfe BE. LaeA-Regulated Fungal Traits Mediate Bacterial Community Assembly. mBio 2023:e0076923. [PMID: 37162223 DOI: 10.1128/mbio.00769-23] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023] Open
Abstract
Potent antimicrobial metabolites are produced by filamentous fungi in pure culture, but their ecological functions in nature are often unknown. Using an antibacterial Penicillium isolate and a cheese rind microbial community, we demonstrate that a fungal specialized metabolite can regulate the diversity of bacterial communities. Inactivation of the global regulator, LaeA, resulted in the loss of antibacterial activity in the Penicillium isolate. Cheese rind bacterial communities assembled with the laeA deletion strain had significantly higher bacterial abundances than the wild-type strain. RNA-sequencing and metabolite profiling demonstrated a striking reduction in the expression and production of the natural product pseurotin in the laeA deletion strain. Inactivation of a core gene in the pseurotin biosynthetic cluster restored bacterial community composition, confirming the role of pseurotins in mediating bacterial community assembly. Our discovery demonstrates how global regulators of fungal transcription can control the assembly of bacterial communities and highlights an ecological role for a widespread class of fungal specialized metabolites. IMPORTANCE Cheese rinds are economically important microbial communities where fungi can impact food quality and aesthetics. The specific mechanisms by which fungi can regulate bacterial community assembly in cheeses, other fermented foods, and microbiomes in general are largely unknown. Our study highlights how specialized metabolites secreted by a Penicillium species can mediate cheese rind development via differential inhibition of bacterial community members. Because LaeA regulates specialized metabolites and other ecologically relevant traits in a wide range of filamentous fungi, this global regulator may have similar impacts in other fungus-dominated microbiomes.
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Affiliation(s)
- Joanna Tannous
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Casey M Cosetta
- Department of Biology, Tufts University, Medford, Massachusetts, USA
| | - Milton T Drott
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- USDA-ARS Cereal Disease Laboratory, St. Paul, Minnesota, USA
| | - Tomás A Rush
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Paul E Abraham
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Richard J Giannone
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Benjamin E Wolfe
- Department of Biology, Tufts University, Medford, Massachusetts, USA
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6
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Seo H, Kang S, Lee D, Yun CW. Regulation of pseurotin A biosynthesis by GliZ and zinc in Aspergillus fumigatus. Sci Rep 2023; 13:2431. [PMID: 36765124 PMCID: PMC9918513 DOI: 10.1038/s41598-023-29753-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 02/09/2023] [Indexed: 02/12/2023] Open
Abstract
Recently, we reported that zinc regulates gliotoxin biosynthesis via ZafA, which is a zinc-responsive transcriptional activator. From an HPLC analysis of culture media of Aspergillus fumigatus, we found a trend of decreasing gliotoxin production but increasing pseurotin A and fumagillin production in proportion to the zinc concentration. The expression of the genes involved in pseurotin A biosynthesis was upregulated under high zinc concentrations. Furthermore, upregulated expression of pseurotin A biosynthetic genes and higher production of pseurotin A were observed in the zafA deletion strain. Interestingly, the deletion of gliZ, a transcriptional activator of gliotoxin biosynthesis genes, resulted in upregulated expression of pseurotin A biosynthetic genes and increased production of pseurotin A. We detected upregulation of fumR expression in the gliZ and zafA deletion mutants. The overexpression of gliZ observed in the zafA deletion mutant resulted in the failure of the mutant to increase pseurotin A production, which is a phenotype of the zafA deletion mutant. These results suggest that ZafA sequentially regulates pseurotin A biosynthesis through GliZ. Finally, we found through a murine virulence test that the gliZ and fumR double-deletion mutants showed a delayed death rate compared with the single-deletion mutants of either gliZ or fumR. Taken together, these results suggested that the biosynthesis of gliotoxin and pseurotin A are regulated in opposite ways by zinc utilization and that each secondary metabolite is synthesized when the synthesis of another secondary metabolite fails to protect it against the defense system of the host.
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Affiliation(s)
- Hyewon Seo
- School of Life Sciences and Biotechnology, Korea University, Anam-Dong, Sungbuk-Gu, Seoul, Republic of Korea
| | - Suzie Kang
- School of Life Sciences and Biotechnology, Korea University, Anam-Dong, Sungbuk-Gu, Seoul, Republic of Korea
| | - Dongho Lee
- Department of Plant Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Cheol-Won Yun
- School of Life Sciences and Biotechnology, Korea University, Anam-Dong, Sungbuk-Gu, Seoul, Republic of Korea.
- NeuroEsgel Co., Anam-Dong, Sungbuk-Gu, Seoul, Republic of Korea.
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Organic Farm Bedded Pack System Microbiomes: A Case Study with Comparisons to Similar and Different Bedded Packs. DAIRY 2022. [DOI: 10.3390/dairy3030042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Animal housing and bedding materials influence cow and farm worker exposure to microbial pathogens, biocontrol agents, and/or allergens. This case study represents an effort to characterize the bacterial and fungal community of bedding systems using an amplicon sequencing approach supplemented with the ecological assessment of cultured Trichocomaceae isolates (focusing on Penicillium and Aspergillus species) and yeasts (Saccharomycetales). Bedding from five certified organic dairy farms in northern Vermont USA were sampled monthly between October 2015 and May 2016. Additional herd level samples from bulk tank milk and two bedding types were collected from two farms to collect fungal isolates for culturing and ecology. Most of the microorganisms in cattle bedding were microbial decomposers (saprophytes) or coprophiles, on account of the bedding being composed of dead plant matter, cattle feces, and urine. Composition of bacterial and fungal communities exhibited distinct patterns of ecological succession measured through time and by bedding depth. Community composition patterns were related to management practices and choice of bedding material. Aspergillus and Penicillium species exhibited niche differentiation expressed as differential substrate requirements; however, they generally exhibited traits of early colonizers of bedding substrates, typically rich in carbon and low in nitrogen. Pichia kudriavzevii was the most prevalent species cultured from milk and bedding. P. kudriavzevii produced protease and its abundance directly related to temperature. The choice of bedding and its management represent a potential opportunity to curate the microbial community of the housing environment.
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Knowles SL, Raja HA, Roberts CD, Oberlies NH. Fungal-fungal co-culture: a primer for generating chemical diversity. Nat Prod Rep 2022; 39:1557-1573. [PMID: 35137758 PMCID: PMC9384855 DOI: 10.1039/d1np00070e] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Indexed: 01/25/2023]
Abstract
Covering: 2002 to 2020In their natural environment, fungi must compete for resources. It has been hypothesized that this competition likely induces the biosynthesis of secondary metabolites for defence. In a quest to discover new chemical diversity from fungal cultures, a growing trend has been to recapitulate this competitive environment in the laboratory, essentially growing fungi in co-culture. This review covers fungal-fungal co-culture studies beginning with the first literature report in 2002. Since then, there has been a growing number of new secondary metabolites reported as a result of fungal co-culture studies. Specifically, this review discusses and provides insights into (1) rationale for pairing fungal strains, (2) ways to grow fungi for co-culture, (3) different approaches to screening fungal co-cultures for chemical diversity, (4) determining the secondary metabolite-producing strain, and (5) final thoughts regarding the fungal-fungal co-culture approach. Our goal is to provide a set of practical strategies for fungal co-culture studies to generate unique chemical diversity that the natural products research community can utilize.
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Affiliation(s)
- Sonja L Knowles
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, USA.
| | - Huzefa A Raja
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, USA.
| | - Christopher D Roberts
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, USA.
| | - Nicholas H Oberlies
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, USA.
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The Chemical Profiling, Docking Study, and Antimicrobial and Antibiofilm Activities of the Endophytic fungi Aspergillus sp. AP5. Molecules 2022; 27:molecules27051704. [PMID: 35268806 PMCID: PMC8911721 DOI: 10.3390/molecules27051704] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 03/02/2022] [Accepted: 03/03/2022] [Indexed: 12/29/2022] Open
Abstract
Growing data suggest that Aspergillus niger, an endophytic fungus, is a rich source of natural compounds with a wide range of biological properties. This study aimed to examine the antimicrobial and antibiofilm capabilities of the Phragmites australis-derived endophyte against a set of pathogenic bacteria and fungi. The endophytic fungus Aspergillus sp. AP5 was isolated from the leaves of P. australis. The chemical profile of the fungal crude extract was identified by spectroscopic analysis using LC-HRESIMS. The fungal-derived extract was evaluated for its antimicrobial activity towards a set of pathogenic bacterial and fungal strains including Staphylococcus aureus, Pseudomonas aeruginosa, Proteus vulgaris, Klebsiella sp., Candida albicans, and Aspergillus niger. Moreover, antibiofilm activity toward four resistant biofilm-forming bacteria was also evaluated. Additionally, a neural-networking pharmacophore-based visual screening predicted the most probable bioactive compounds in the obtained extract. The AP5-EtOAc extract was found to have potent antibacterial activities against S. aureus, E. coli, and Klebsiella sp., while it exhibited low antibacterial activity toward P. Vulgaris and P. aeruginosa and displayed anticandidal activity. The AP5-EtOAc extract had significant antibiofilm activity in S. aureus, followed by P. aeruginosa. The active metabolites’ antifungal and/or antibacterial activities may be due to targeting the fungal CYP 51 and/or the bacterial Gyr-B.
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Interactive Inhibition of Aflatoxigenic Aspergillus flavus and Ochratoxigenic Aspergillus carbonarius by Aspergillus oryzae under Fluctuating Temperatures. MICROBIOLOGY RESEARCH 2022. [DOI: 10.3390/microbiolres13010009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
This study aimed to evaluate the effectiveness of A. oryzae in inhibiting aflatoxin B1 (AFB1) and ochratoxin A (OTA) production by A. flavus and A. carbonarius, respectively, under shifting temperatures. A. oryzae was tested on different agar, namely coconut cream agar (CCA) and chili-based agar to figure out the variation in the effectiveness of A. oryzae on the most appropriate medium for A. flavus and A. carbonarius to produce mycotoxin and under natural condition where they are predominantly found. On CCA, the temperatures applied were 20, 30, 35, 40, 20/30, 20/35, and 20/40 °C, while on chili-based agar, the temperatures imposed were 20, 40, and 20/40 °C, at varied water activity of 0.92 and 0.97aw. The findings indicated that A. oryzae was much more effective in inhibiting the growth of A. flavus rather than A. carbonarius, yet it was able to inhibit higher OTA concentration than AFB1 at fluctuating temperatures on CCA as the most appropriate medium for A. flavus and A. carbonarius. A. oryzae effectively inhibited AFB1 and OTA at static temperature of 20 °C and water activity of 0.97aw on chili-based agar. Under fluctuating temperatures (20/40 °C), A. oryzae was also able to control mycotoxin, particularly OTA at high water activity (0.97aw).
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11
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de Castro PA, Colabardini AC, Moraes M, Horta MAC, Knowles SL, Raja HA, Oberlies NH, Koyama Y, Ogawa M, Gomi K, Steenwyk JL, Rokas A, Gonçales RA, Duarte-Oliveira C, Carvalho A, Ries LNA, Goldman GH. Regulation of gliotoxin biosynthesis and protection in Aspergillus species. PLoS Genet 2022; 18:e1009965. [PMID: 35041649 PMCID: PMC8797188 DOI: 10.1371/journal.pgen.1009965] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/28/2022] [Accepted: 01/04/2022] [Indexed: 02/07/2023] Open
Abstract
Aspergillus fumigatus causes a range of human and animal diseases collectively known as aspergillosis. A. fumigatus possesses and expresses a range of genetic determinants of virulence, which facilitate colonisation and disease progression, including the secretion of mycotoxins. Gliotoxin (GT) is the best studied A. fumigatus mycotoxin with a wide range of known toxic effects that impair human immune cell function. GT is also highly toxic to A. fumigatus and this fungus has evolved self-protection mechanisms that include (i) the GT efflux pump GliA, (ii) the GT neutralising enzyme GliT, and (iii) the negative regulation of GT biosynthesis by the bis-thiomethyltransferase GtmA. The transcription factor (TF) RglT is the main regulator of GliT and this GT protection mechanism also occurs in the non-GT producing fungus A. nidulans. However, the A. nidulans genome does not encode GtmA and GliA. This work aimed at analysing the transcriptional response to exogenous GT in A. fumigatus and A. nidulans, two distantly related Aspergillus species, and to identify additional components required for GT protection. RNA-sequencing shows a highly different transcriptional response to exogenous GT with the RglT-dependent regulon also significantly differing between A. fumigatus and A. nidulans. However, we were able to observe homologs whose expression pattern was similar in both species (43 RglT-independent and 11 RglT-dependent). Based on this approach, we identified a novel RglT-dependent methyltranferase, MtrA, involved in GT protection. Taking into consideration the occurrence of RglT-independent modulated genes, we screened an A. fumigatus deletion library of 484 transcription factors (TFs) for sensitivity to GT and identified 15 TFs important for GT self-protection. Of these, the TF KojR, which is essential for kojic acid biosynthesis in Aspergillus oryzae, was also essential for virulence and GT biosynthesis in A. fumigatus, and for GT protection in A. fumigatus, A. nidulans, and A. oryzae. KojR regulates rglT, gliT, gliJ expression and sulfur metabolism in Aspergillus species. Together, this study identified conserved components required for GT protection in Aspergillus species. A. fumigatus secretes mycotoxins that are essential for its virulence and pathogenicity. Gliotoxin (GT) is a sulfur-containing mycotoxin, which is known to impair several aspects of the human immune response. GT is also toxic to different fungal species, which have evolved several GT protection strategies. To further decipher these responses, we used transcriptional profiling aiming to compare the response to GT in the GT producer A. fumigatus and the GT non-producer A. nidulans. This analysis allowed us to identify additional genes with a potential role in GT protection. We also identified 15 transcription factors (TFs) encoded in the A. fumigatus genome that are important for conferring resistance to exogenous gliotoxin. One of these TFs, KojR, which is essential for A. oryzae kojic acid production, is also important for virulence in A. fumigatus and GT protection in A. fumigatus, A. nidulans and A. oryzae. KojR regulates the expression of genes important for gliotoxin biosynthesis and protection, and sulfur metabolism. Together, this work identified conserved components required for gliotoxin protection in Aspergillus species.
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Affiliation(s)
- Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Ana Cristina Colabardini
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Maísa Moraes
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | | | - Sonja L. Knowles
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina United States of America
| | - Huzefa A. Raja
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina United States of America
| | - Nicholas H. Oberlies
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina United States of America
| | - Yasuji Koyama
- Noda Institute for Scientific Research, 338 Noda, Chiba, Japan
| | - Masahiro Ogawa
- Noda Institute for Scientific Research, 338 Noda, Chiba, Japan
| | - Katsuya Gomi
- Department of Bioindustrial Informatics and Genomics, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Jacob L. Steenwyk
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Relber A. Gonçales
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B’s—PT Government Associate Laboratory, Guimarães/Braga, Portugal
| | - Cláudio Duarte-Oliveira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B’s—PT Government Associate Laboratory, Guimarães/Braga, Portugal
| | - Agostinho Carvalho
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B’s—PT Government Associate Laboratory, Guimarães/Braga, Portugal
| | - Laure N. A. Ries
- MRC Centre for Medical Mycology at the University of Exeter, Geoffrey Pope Building, Exeter, United Kingdom
- * E-mail: (LNAR); (GHG)
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
- * E-mail: (LNAR); (GHG)
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12
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Steenwyk JL, Mead ME, de Castro PA, Valero C, Damasio A, dos Santos RAC, Labella AL, Li Y, Knowles SL, Raja HA, Oberlies NH, Zhou X, Cornely OA, Fuchs F, Koehler P, Goldman GH, Rokas A. Genomic and Phenotypic Analysis of COVID-19-Associated Pulmonary Aspergillosis Isolates of Aspergillus fumigatus. Microbiol Spectr 2021; 9:e0001021. [PMID: 34106569 PMCID: PMC8552514 DOI: 10.1128/spectrum.00010-21] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 04/08/2021] [Indexed: 02/06/2023] Open
Abstract
The ongoing global pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for coronavirus disease 2019 (COVID-19), first described in Wuhan, China. A subset of COVID-19 patients has been reported to have acquired secondary infections by microbial pathogens, such as opportunistic fungal pathogens from the genus Aspergillus. To gain insight into COVID-19-associated pulmonary aspergillosis (CAPA), we analyzed the genomes and characterized the phenotypic profiles of four CAPA isolates of Aspergillus fumigatus obtained from patients treated in the area of North Rhine-Westphalia, Germany. By examining the mutational spectrum of single nucleotide polymorphisms, insertion-deletion polymorphisms, and copy number variants among 206 genes known to modulate A. fumigatus virulence, we found that CAPA isolate genomes do not exhibit significant differences from the genome of the Af293 reference strain. By examining a number of factors, including virulence in an invertebrate moth model, growth in the presence of osmotic, cell wall, and oxidative stressors, secondary metabolite biosynthesis, and the MIC of antifungal drugs, we found that CAPA isolates were generally, but not always, similar to A. fumigatus reference strains Af293 and CEA17. Notably, CAPA isolate D had more putative loss-of-function mutations in genes known to increase virulence when deleted. Moreover, CAPA isolate D was significantly more virulent than the other three CAPA isolates and the A. fumigatus reference strains Af293 and CEA17, but similarly virulent to two other clinical strains of A. fumigatus. These findings expand our understanding of the genomic and phenotypic characteristics of isolates that cause CAPA. IMPORTANCE The global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19), has already killed millions of people. COVID-19 patient outcome can be further complicated by secondary infections, such as COVID-19-associated pulmonary aspergillosis (CAPA). CAPA is caused by Aspergillus fungal pathogens, but there is little information about the genomic and phenotypic characteristics of CAPA isolates. We conducted genome sequencing and extensive phenotyping of four CAPA isolates of Aspergillus fumigatus from Germany. We found that CAPA isolates were often, but not always, similar to other reference strains of A. fumigatus across 206 genetic determinants of infection-relevant phenotypes, including virulence. For example, CAPA isolate D was more virulent than other CAPA isolates and reference strains in an invertebrate model of fungal disease, but similarly virulent to two other clinical strains. These results expand our understanding of COVID-19-associated pulmonary aspergillosis.
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Affiliation(s)
- Jacob L. Steenwyk
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Matthew E. Mead
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Clara Valero
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - André Damasio
- Institute of Biology, University of Campinas (UNICAMP), Campinas-SP, Brazil
- Experimental Medicine Research Cluster (EMRC), University of Campinas (UNICAMP), Campinas-SP, Brazil
| | - Renato A. C. dos Santos
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Abigail L. Labella
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Yuanning Li
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Sonja L. Knowles
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Huzefa A. Raja
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Nicholas H. Oberlies
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Xiaofan Zhou
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Oliver A. Cornely
- University of Cologne, Medical Faculty and University Hospital Cologne, Department I of Internal Medicine, Excellence Center for Medical Mycology (ECMM), Cologne, Germany
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
- ZKS Köln, Clinical Trials Centre Cologne, Cologne, Germany
- German Center for Infection Research (DZIF), Partner Site Bonn‐Cologne, Medical Faculty and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Frieder Fuchs
- Faculty of Medicine, Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, Cologne, Germany
| | - Philipp Koehler
- University of Cologne, Medical Faculty and University Hospital Cologne, Department I of Internal Medicine, Excellence Center for Medical Mycology (ECMM), Cologne, Germany
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
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Ching'anda C, Atehnkeng J, Bandyopadhyay R, Callicott KA, Orbach MJ, Mehl HL, Cotty PJ. Temperature Influences on Interactions Among Aflatoxigenic Species of Aspergillus Section Flavi During Maize Colonization. FRONTIERS IN FUNGAL BIOLOGY 2021; 2:720276. [PMID: 37744097 PMCID: PMC10512225 DOI: 10.3389/ffunb.2021.720276] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 07/26/2021] [Indexed: 09/26/2023]
Abstract
Fungal species within Aspergillus section Flavi contaminate food and feed with aflatoxins. These toxic fungal metabolites compromise human and animal health and disrupt trade. Genotypically and phenotypically diverse species co-infect crops, but temporal and spatial variation in frequencies of different lineages suggests that environmental factors such as temperature may influence structure of aflatoxin-producing fungal communities. Furthermore, though most species within Aspergillus section Flavi produce sclerotia, divergent sclerotial morphologies (small or S-type sclerotia vs. large or L-type sclerotia) and differences in types and quantities of aflatoxins produced suggest lineages are adapted to different life strategies. Temperature is a key parameter influencing pre- and post-harvest aflatoxin contamination of crops. We tested the hypothesis that species of aflatoxin-producing fungi that differ in sclerotial morphology will vary in competitive ability and that outcomes of competition and aflatoxin production will be modulated by temperature. Paired competition experiments between highly aflatoxigenic S-type species (A. aflatoxiformans and Lethal Aflatoxicosis Fungus) and L-type species (A. flavus L morphotype and A. parasiticus) were conducted on maize kernels at 25 and 30°C. Proportions of each isolate growing within and sporulating on kernels were measured using quantitative pyrosequencing. At 30°C, S-type fungi were more effective at host colonization compared to L-type isolates. Total aflatoxins and the proportion of B vs. G aflatoxins were greater at 30°C compared to 25°C. Sporulation by L-type isolates was reduced during competition with S-type fungi at 30°C, while relative quantities of conidia produced by S-type species either increased or did not change during competition. Results indicate that both species interactions and temperature can shape population structure of Aspergillus section Flavi, with warmer temperatures favoring growth and dispersal of highly toxigenic species with S-type sclerotia.
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Affiliation(s)
- Connel Ching'anda
- School of Plant Sciences, University of Arizona, Tucson, AZ, United States
| | - Joseph Atehnkeng
- International Institute of Tropical Agriculture (IITA), Lilongwe, Malawi
| | | | - Kenneth A. Callicott
- United States Department of Agriculture - Agriculture Research Service, Tucson, AZ, United States
| | - Marc J. Orbach
- School of Plant Sciences, University of Arizona, Tucson, AZ, United States
| | - Hillary L. Mehl
- United States Department of Agriculture - Agriculture Research Service, Tucson, AZ, United States
| | - Peter J. Cotty
- School of Plant Sciences, University of Arizona, Tucson, AZ, United States
- United States Department of Agriculture - Agriculture Research Service, Tucson, AZ, United States
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
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14
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Stierle AA, Stierle DB, Decato D, Alverson J, Apedaile L. Cryptic Biosynthesis of the Berkeleypenostatins from Coculture of Extremophilic Penicillium sp. JOURNAL OF NATURAL PRODUCTS 2021; 84:1656-1665. [PMID: 33957049 PMCID: PMC8574098 DOI: 10.1021/acs.jnatprod.1c00248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Coculture fermentation of Penicillium fuscum and P. camembertii/clavigerum yielded berkeleypenostatins A-G (1-7) as well as the previously reported berkeleylactones A-H, the known macrolide A26771B, citrinin, and patulin. As was true with the berkeleylactones, there was no evidence of the berkeleypenostatins in either axenic culture. The structures were deduced from analyses of spectral data, and the absolute configuration of berkeleypenostatin A (1) was determined by single-crystal X-ray crystallography. Berkeleypenostatins A (1) and E (5) inhibited migration of human pancreatic carcinoma cells (HPAF-II). Both compounds were tested by the NCI Developmental Therapeutics Program. In the NCI 60 cell five-dose screen, berkeleypenostatin E (5) was the more active of the two, with 1-10 μM total growth inhibition (TGI) of all leukemia cell lines, as well as the majority of colon, CNS, melanoma, ovarian, prostate, renal, and breast cancer cell lines.
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Affiliation(s)
| | | | | | | | - Lily Apedaile
- UM Health & Medicine Director, Western Montana Area Health Education Center University of Montana, Missoula, Montana
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15
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Gimeno A, Stanley CE, Ngamenie Z, Hsung MH, Walder F, Schmieder SS, Bindschedler S, Junier P, Keller B, Vogelgsang S. A versatile microfluidic platform measures hyphal interactions between Fusarium graminearum and Clonostachys rosea in real-time. Commun Biol 2021; 4:262. [PMID: 33637874 PMCID: PMC7910300 DOI: 10.1038/s42003-021-01767-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 01/29/2021] [Indexed: 02/07/2023] Open
Abstract
Routinely, fungal-fungal interactions (FFI) are studied on agar surfaces. However, this format restricts high-resolution dynamic imaging. To gain experimental access to FFI at the hyphal level in real-time, we developed a microfluidic platform, a FFI device. This device utilises microchannel geometry to enhance the visibility of hyphal growth and provides control channels to allow comparisons between localised and systemic effects. We demonstrate its function by investigating the FFI between the biological control agent (BCA) Clonostachys rosea and the plant pathogen Fusarium graminearum. Microscope image analyses confirm the inhibitory effect of the necrotrophic BCA and we show that a loss of fluorescence in parasitised hyphae of GFP-tagged F. graminearum coincides with the detection of GFP in mycelium of C. rosea. The versatility of our device to operate under both water-saturated and nutrient-rich as well as dry and nutrient-deficient conditions, coupled with its spatio-temporal output, opens new opportunities to study relationships between fungi.
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Affiliation(s)
- Alejandro Gimeno
- Ecological Plant Protection in Arable Crops, Plant Protection, Agroscope, Zurich, Switzerland
- Molecular Plant Biology and Phytopathology, Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Claire E Stanley
- Institute for Chemical and Bioengineering, ETH Zürich, Zürich, Switzerland.
- Plant-Soil Interactions, Agroecology and Environment Research Division, Agroscope, Zurich, Switzerland.
- Department of Bioengineering, Imperial College London, London, UK.
| | - Zacharie Ngamenie
- Ecological Plant Protection in Arable Crops, Plant Protection, Agroscope, Zurich, Switzerland
| | - Ming-Hui Hsung
- Plant-Soil Interactions, Agroecology and Environment Research Division, Agroscope, Zurich, Switzerland
| | - Florian Walder
- Plant-Soil Interactions, Agroecology and Environment Research Division, Agroscope, Zurich, Switzerland
| | - Stefanie S Schmieder
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
- Division of Gastroenterology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Pilar Junier
- Laboratory of Microbiology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Beat Keller
- Molecular Plant Biology and Phytopathology, Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Susanne Vogelgsang
- Ecological Plant Protection in Arable Crops, Plant Protection, Agroscope, Zurich, Switzerland.
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16
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Steenwyk JL, Mead ME, de Castro PA, Valero C, Damasio A, dos Santos RAC, Labella AL, Li Y, Knowles SL, Raja HA, Oberlies NH, Zhou X, Cornely OA, Fuchs F, Koehler P, Goldman GH, Rokas A. Genomic and phenotypic analysis of COVID-19-associated pulmonary aspergillosis isolates of Aspergillus fumigatus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020:2020.11.06.371971. [PMID: 33173866 PMCID: PMC7654854 DOI: 10.1101/2020.11.06.371971] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The ongoing global pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the coronavirus disease 2019 (COVID-19) first described from Wuhan, China. A subset of COVID-19 patients has been reported to have acquired secondary infections by microbial pathogens, such as fungal opportunistic pathogens from the genus Aspergillus . To gain insight into COVID-19 associated pulmonary aspergillosis (CAPA), we analyzed the genomes and characterized the phenotypic profiles of four CAPA isolates of Aspergillus fumigatus obtained from patients treated in the area of North Rhine-Westphalia, Germany. By examining the mutational spectrum of single nucleotide polymorphisms, insertion-deletion polymorphisms, and copy number variants among 206 genes known to modulate A. fumigatus virulence, we found that CAPA isolate genomes do not exhibit major differences from the genome of the Af293 reference strain. By examining virulence in an invertebrate moth model, growth in the presence of osmotic, cell wall, and oxidative stressors, and the minimum inhibitory concentration of antifungal drugs, we found that CAPA isolates were generally, but not always, similar to A. fumigatus reference strains Af293 and CEA17. Notably, CAPA isolate D had more putative loss of function mutations in genes known to increase virulence when deleted (e.g., in the FLEA gene, which encodes a lectin recognized by macrophages). Moreover, CAPA isolate D was significantly more virulent than the other three CAPA isolates and the A. fumigatus reference strains tested. These findings expand our understanding of the genomic and phenotypic characteristics of isolates that cause CAPA.
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Affiliation(s)
- Jacob L. Steenwyk
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Matthew E. Mead
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Clara Valero
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - André Damasio
- Institute of Biology, University of Campinas (UNICAMP), Campinas-SP, Brazil
- Experimental Medicine Research Cluster (EMRC), University of Campinas (UNICAMP), Campinas-SP, Brazil
| | - Renato A. C. dos Santos
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Abigail L. Labella
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Yuanning Li
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Sonja L. Knowles
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina 27402
| | - Huzefa A. Raja
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina 27402
| | - Nicholas H. Oberlies
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina 27402
| | - Xiaofan Zhou
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Oliver A. Cornely
- University of Cologne, Medical Faculty and University Hospital Cologne, Department I of Internal Medicine, Excellence Center for Medical Mycology (ECMM), Cologne, Germany
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
- ZKS Köln, Clinical Trials Centre Cologne, Cologne, Germany
- German Center for Infection Research (DZIF), Partner Site Bonn Cologne, Medical Faculty and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Frieder Fuchs
- Faculty of Medicine, Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, Cologne, Germany
| | - Philipp Koehler
- University of Cologne, Medical Faculty and University Hospital Cologne, Department I of Internal Medicine, Excellence Center for Medical Mycology (ECMM), Cologne, Germany
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
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Viegas C, Dias M, Almeida B, Carolino E, Viegas S. Aspergillus spp. presence on mechanical protection gloves from the waste sorting industry. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2020; 17:523-530. [PMID: 33206026 DOI: 10.1080/15459624.2020.1834113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The organic material present on waste sorting units serve as a substrate for different microorganisms, increasing workers' exposure to Aspergillus spp. This study intends to assess the Aspergillus spp. contamination on Mechanical Protection Gloves (MPG) from different workstations and understand the role of MPG in workers' exposure to these genera. Sixty-seven used MPG were collected from different workstations and extracts were seeded on malt extract agar (MEA) supplemented with chloramphenicol (0.05%) and dichloran glycerol (DG18). The same extracts were used for the molecular detection of fungal species/strains, with reported toxigenic potential, namely Aspergillus sections (Circumdati, Flavi, Fumigati, and Nidulantes). Among Aspergillus spp., the sections with the highest prevalence on MEA were Nigri (88.29%) and Fumigati (8.63%), whereas on DG18 were Nigri (31.79%) and Circumdati (30.77%). Aspergillus section Circumdati was detected in 22 MPG samples by RT-PCR (32.84%), Fumigati in 59 samples (88.06%), Nidulantes in 61 samples (91.05%), and Flavi in 6 samples (8.96%). It was showed that, even with daily replacement, MPG presented Aspergillus spp. contamination. Thus, a more regular replacement of MPG and the adoption of complementary hygienic procedures by workers are critical to guarantee workers' protection in this occupational environment.
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Affiliation(s)
- Carla Viegas
- H&TRC- Health & Technology Research Center, ESTeSL- Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, Lisbon, Portugal
- NOVA National School of Public Health, Public Health Research Centre Universidade NOVA de Lisboa, Lisbon, Portugal
- Comprehensive Health Research Center (CHRC), Lisbon, Portugal
| | - Marta Dias
- H&TRC- Health & Technology Research Center, ESTeSL- Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, Lisbon, Portugal
| | - Beatriz Almeida
- H&TRC- Health & Technology Research Center, ESTeSL- Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, Lisbon, Portugal
| | - Elisabete Carolino
- H&TRC- Health & Technology Research Center, ESTeSL- Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, Lisbon, Portugal
| | - Susana Viegas
- H&TRC- Health & Technology Research Center, ESTeSL- Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, Lisbon, Portugal
- NOVA National School of Public Health, Public Health Research Centre Universidade NOVA de Lisboa, Lisbon, Portugal
- Comprehensive Health Research Center (CHRC), Lisbon, Portugal
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Steenwyk JL, Mead ME, Knowles SL, Raja HA, Roberts CD, Bader O, Houbraken J, Goldman GH, Oberlies NH, Rokas A. Variation Among Biosynthetic Gene Clusters, Secondary Metabolite Profiles, and Cards of Virulence Across Aspergillus Species. Genetics 2020; 216:481-497. [PMID: 32817009 PMCID: PMC7536862 DOI: 10.1534/genetics.120.303549] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 08/01/2020] [Indexed: 02/07/2023] Open
Abstract
Aspergillus fumigatus is a major human pathogen. In contrast, Aspergillus fischeri and the recently described Aspergillus oerlinghausenensis, the two species most closely related to A. fumigatus, are not known to be pathogenic. Some of the genetic determinants of virulence (or "cards of virulence") that A. fumigatus possesses are secondary metabolites that impair the host immune system, protect from host immune cell attacks, or acquire key nutrients. To examine whether secondary metabolism-associated cards of virulence vary between these species, we conducted extensive genomic and secondary metabolite profiling analyses of multiple A. fumigatus, one A. oerlinghausenensis, and multiple A. fischeri strains. We identified two cards of virulence (gliotoxin and fumitremorgin) shared by all three species and three cards of virulence (trypacidin, pseurotin, and fumagillin) that are variable. For example, we found that all species and strains examined biosynthesized gliotoxin, which is known to contribute to virulence, consistent with the conservation of the gliotoxin biosynthetic gene cluster (BGC) across genomes. For other secondary metabolites, such as fumitremorgin, a modulator of host biology, we found that all species produced the metabolite but that there was strain heterogeneity in its production within species. Finally, species differed in their biosynthesis of fumagillin and pseurotin, both contributors to host tissue damage during invasive aspergillosis. A. fumigatus biosynthesized fumagillin and pseurotin, while A. oerlinghausenensis biosynthesized fumagillin and A. fischeri biosynthesized neither. These biochemical differences were reflected in sequence divergence of the intertwined fumagillin/pseurotin BGCs across genomes. These results delineate the similarities and differences in secondary metabolism-associated cards of virulence between a major fungal pathogen and its nonpathogenic closest relatives, shedding light onto the genetic and phenotypic changes associated with the evolution of fungal pathogenicity.
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Affiliation(s)
- Jacob L Steenwyk
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235
| | - Matthew E Mead
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235
| | - Sonja L Knowles
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina 27402
| | - Huzefa A Raja
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina 27402
| | - Christopher D Roberts
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina 27402
| | - Oliver Bader
- Institute for Medical Microbiology, University Medical Center Göttingen, 37075, Germany
| | - Jos Houbraken
- Westerdijk Fungal Biodiversity Institute, 3584 CT Utrecht, The Netherlands
| | - Gustavo H Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, 14040-900 Brazil
| | - Nicholas H Oberlies
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, North Carolina 27402
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235
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19
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Statistical optimization of production parameters for enhanced lovastatin production from endophytic Aspergillus terreus. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2020. [DOI: 10.1016/j.bcab.2020.101787] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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20
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Knowles SL, Raja HA, Isawi IH, Flores-Bocanegra L, Reggio PH, Pearce CJ, Burdette JE, Rokas A, Oberlies NH. Wheldone: Characterization of a Unique Scaffold from the Coculture of Aspergillus fischeri and Xylaria flabelliformis. Org Lett 2020; 22:1878-1882. [PMID: 32096649 PMCID: PMC7153779 DOI: 10.1021/acs.orglett.0c00219] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
Wheldone (1) was isolated and elucidated from a coculture of Aspergillus
fischeri (NRRL 181) and Xylaria flabelliformis (G536), where secondary metabolite biosynthesis was stimulated by
antagonism between these fungi. First observed via in situ analysis between these competing fungal cultures, the conditions
were scaled to reproducibly generate 1, whose novel structure
was elucidated by one- and two-dimensional NMR and mass spectrometry.
Compound 1 displayed cytotoxic activity against breast,
ovarian, and melanoma cancer cell lines.
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Affiliation(s)
- Sonja L Knowles
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Huzefa A Raja
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Israa H Isawi
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Laura Flores-Bocanegra
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Patricia H Reggio
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Cedric J Pearce
- Mycosynthetix, Inc., Hillsborough, North Carolina 27278, United States
| | - Joanna E Burdette
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, Illinois 60612, United States
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Nicholas H Oberlies
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
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21
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Abo Nouh FA, Gezaf SA, Abdel-Azeem AM. Aspergillus Mycotoxins: Potential as Biocontrol Agents. Fungal Biol 2020. [DOI: 10.1007/978-3-030-48474-3_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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22
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Rawlinson C, See PT, Moolhuijzen P, Li H, Moffat CS, Chooi YH, Oliver RP. The identification and deletion of the polyketide synthase-nonribosomal peptide synthase gene responsible for the production of the phytotoxic triticone A/B in the wheat fungal pathogen Pyrenophora tritici-repentis. Environ Microbiol 2019; 21:4875-4886. [PMID: 31698543 PMCID: PMC6915911 DOI: 10.1111/1462-2920.14854] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 11/04/2019] [Accepted: 11/05/2019] [Indexed: 12/21/2022]
Abstract
The economically important necrotrophic fungal pathogen, Pyrenophora tritici-repentis (Ptr), causes tan spot of wheat, a disease typified by foliar necrosis and chlorosis. The culture filtrate of an Australian Ptr isolate, M4, possesses phytotoxic activity and plant bioassay guided discovery led to the purification of necrosis inducing toxins called triticone A and B. High-resolution LC-MS/MS analysis of the culture filtrate identified an additional 37 triticone-like compounds. The biosynthetic gene cluster responsible for triticone production (the Ttc cluster) was identified and deletion of TtcA, a hybrid polyketide synthase (PKS)-nonribosomal peptide synthase (NRPS), abolished production of all triticones. The pathogenicity of mutant (ttcA) strains was not visibly affected in our assays. We hypothesize that triticones possess general antimicrobial activity important for competition in multi-microbial environments.
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Affiliation(s)
- Catherine Rawlinson
- Centre for Crop and Disease Management, Curtin University, Perth, 6150, Western Australia, Australia
| | - Pao Theen See
- Centre for Crop and Disease Management, Curtin University, Perth, 6150, Western Australia, Australia
| | - Paula Moolhuijzen
- Centre for Crop and Disease Management, Curtin University, Perth, 6150, Western Australia, Australia
| | - Hang Li
- School of Molecular Sciences, The University of Western Australia, Perth, 6009, Western Australia, Australia
| | - Caroline S Moffat
- Centre for Crop and Disease Management, Curtin University, Perth, 6150, Western Australia, Australia
| | - Yit-Heng Chooi
- School of Molecular Sciences, The University of Western Australia, Perth, 6009, Western Australia, Australia
| | - Richard P Oliver
- Centre for Crop and Disease Management, Curtin University, Perth, 6150, Western Australia, Australia
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23
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Popiel D, Dawidziuk A, Koczyk G. Efflux pumps as an additional source of resistance to trichothecenes in Fusarium proliferatum and Fusarium oxysporum isolates. J Appl Genet 2019; 60:405-416. [PMID: 31250288 PMCID: PMC6803570 DOI: 10.1007/s13353-019-00501-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 06/05/2019] [Accepted: 06/11/2019] [Indexed: 11/30/2022]
Abstract
Role of efflux-mediated toxin resistance to trichothecenes is known in trichothecene-producing species. However, the role of trichothecene efflux pump homologues in non-producing fusaria such as F. oxysporum and F. proliferatum was not investigated in detail. Analysis of the homologues of trichothecene efflux pump from multiple fungal species allowed us to uncover and catalogue functional gene copies of conserved structure. Putative Tri12 candidates in Fusarium oxysporum and F. proliferatum were characterised via expression profiling in response to different trigger compounds, providing supporting evidence for role of Tri12 homologues in the resistance to trichothecenes. Our analysis of Tri12 phylogeny also suggests that efflux-mediated trichothecene resistance is likely to predate the divergence of Trichoderma and Fusarium species. On the regulatory level, we posit that the increased tolerance of trichothecenes by F. oxysporum is possibly related to the decoupling of Tri12 homologue expression from pH, due to the deletion of PACC/RIM101 transcription factor binding site in its promoter region.
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Affiliation(s)
- Delfina Popiel
- Department of Pathogen Genetics and Plant Resistance, Institute of Plant Genetics, Polish Academy of Sciences, Strzeszynska 34, Poznan, Poland.
| | - Adam Dawidziuk
- Department of Pathogen Genetics and Plant Resistance, Institute of Plant Genetics, Polish Academy of Sciences, Strzeszynska 34, Poznan, Poland
| | - Grzegorz Koczyk
- Department of Biometry and Bioinformatics, Institute of Plant Genetics, Polish Academy of Sciences, Strzeszynska 34, Poznan, Poland
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24
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Boruta T, Milczarek I, Bizukojc M. Evaluating the outcomes of submerged co-cultivation: production of lovastatin and other secondary metabolites by Aspergillus terreus in fungal co-cultures. Appl Microbiol Biotechnol 2019; 103:5593-5605. [PMID: 31098686 PMCID: PMC6597594 DOI: 10.1007/s00253-019-09874-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 04/24/2019] [Accepted: 04/26/2019] [Indexed: 01/06/2023]
Abstract
The goal of the study was to compare the production of secondary metabolites by Aspergillus terreus ATCC 20542 under the conditions of submerged mono- and co-cultivation. The suggested experimental scheme encompassed a diverse set of co-culture initiation strategies differing mostly with respect to the development stage of tested fungal strains at the moment of their confrontation. Three species of filamentous fungi exhibiting distinct patterns of morphological evolution under submerged conditions, namely Penicillium rubens, Chaetomium globosum, and Mucor racemosus, were selected as the co-cultivation partners of A. terreus. The choice of the co-cultivated species and the approach of co-culture triggering noticeably influenced the levels of lovastatin (mevinolinic acid), (+)-geodin, asterric acid, and butyrolactone I in the broth. Even though the evaluated co-cultures did not lead to the increased titers of lovastatin relative to standard monocultures, the biosynthesis of the remaining three metabolites was either enhanced or inhibited depending on the experimental variant. The production of butyrolactone I turned out to be particularly affected by the presence of C. globosum. Interestingly, in the A. terreus/C. globosum co-cultures, the decrease of lovastatin concentration was recorded. According to the most probable scenario, lovastatin was in this case converted to monacolin J acid, a polyketide molecule that may be applied as a substrate for the synthesis of statin drugs. The study revealed that the spores of two distinct fungal species, namely A. terreus and C. globosum, co-agglomerate under submerged conditions to form pellets. Finally, the biosynthetic performance of co-cultures involving four fungal species was evaluated.
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Affiliation(s)
- Tomasz Boruta
- Faculty of Process and Environmental Engineering, Department of Bioprocess Engineering, Lodz University of Technology, ul. Wolczanska 213, 90-924, Lodz, Poland.
| | - Iwona Milczarek
- Faculty of Process and Environmental Engineering, Department of Bioprocess Engineering, Lodz University of Technology, ul. Wolczanska 213, 90-924, Lodz, Poland
| | - Marcin Bizukojc
- Faculty of Process and Environmental Engineering, Department of Bioprocess Engineering, Lodz University of Technology, ul. Wolczanska 213, 90-924, Lodz, Poland
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25
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Knowles SL, Raja HA, Wright AJ, Lee AML, Caesar LK, Cech NB, Mead ME, Steenwyk JL, Ries LNA, Goldman GH, Rokas A, Oberlies NH. Mapping the Fungal Battlefield: Using in situ Chemistry and Deletion Mutants to Monitor Interspecific Chemical Interactions Between Fungi. Front Microbiol 2019; 10:285. [PMID: 30837981 PMCID: PMC6389630 DOI: 10.3389/fmicb.2019.00285] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 02/04/2019] [Indexed: 11/13/2022] Open
Abstract
Fungi grow in competitive environments, and to cope, they have evolved strategies, such as the ability to produce a wide range of secondary metabolites. This begs two related questions. First, how do secondary metabolites influence fungal ecology and interspecific interactions? Second, can these interspecific interactions provide a way to “see” how fungi respond, chemically, within a competitive environment? To evaluate these, and to gain insight into the secondary metabolic arsenal fungi possess, we co-cultured Aspergillus fischeri, a genetically tractable fungus that produces a suite of mycotoxins, with Xylaria cubensis, a fungus that produces the fungistatic compound and FDA-approved drug, griseofulvin. To monitor and characterize fungal chemistry in situ, we used the droplet-liquid microjunction-surface sampling probe (droplet probe). The droplet probe makes a microextraction at defined locations on the surface of the co-culture, followed by analysis of the secondary metabolite profile via liquid chromatography-mass spectrometry. Using this, we mapped and compared the spatial profiles of secondary metabolites from both fungi in monoculture versus co-culture. X. cubensis predominantly biosynthesized griseofulvin and dechlorogriseofulvin in monoculture. In contrast, under co-culture conditions a deadlock was formed between the two fungi, and X. cubensis biosynthesized the same two secondary metabolites, along with dechloro-5′-hydroxygriseofulvin and 5′-hydroxygriseofulvin, all of which have fungistatic properties, as well as mycotoxins like cytochalasin D and cytochalasin C. In contrast, in co-culture, A. fischeri increased the production of the mycotoxins fumitremorgin B and verruculogen, but otherwise remained unchanged relative to its monoculture. To evaluate that secondary metabolites play an important role in defense and territory establishment, we co-cultured A. fischeri lacking the master regulator of secondary metabolism laeA with X. cubensis. We found that the reduced secondary metabolite biosynthesis of the ΔlaeA strain of A. fischeri eliminated the organism’s ability to compete in co-culture and led to its displacement by X. cubensis. These results demonstrate the potential of in situ chemical analysis and deletion mutant approaches for shedding light on the ecological roles of secondary metabolites and how they influence fungal ecological strategies; co-culturing may also stimulate the biosynthesis of secondary metabolites that are not produced in monoculture in the laboratory.
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Affiliation(s)
- Sonja L Knowles
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, United States
| | - Huzefa A Raja
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, United States
| | - Allison J Wright
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, United States
| | - Ann Marie L Lee
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, United States
| | - Lindsay K Caesar
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, United States
| | - Nadja B Cech
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, United States
| | - Matthew E Mead
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
| | - Jacob L Steenwyk
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
| | - Laure N A Ries
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Gustavo H Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
| | - Nicholas H Oberlies
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, United States
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26
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Esmaeilishirazifard E, Dariush A, Moschos SA, Keshavarz T. A novel antifungal property for the Bacillus licheniformis ComX pheromone and its possible role in inter-kingdom cross-talk. Appl Microbiol Biotechnol 2018; 102:5197-5208. [DOI: 10.1007/s00253-018-9004-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 03/20/2018] [Accepted: 04/09/2018] [Indexed: 01/13/2023]
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27
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Co-inoculum of Beauveria brongniartii and B. bassiana shows in vitro different metabolic behaviour in comparison to single inoculums. Sci Rep 2017; 7:13102. [PMID: 29026120 PMCID: PMC5638874 DOI: 10.1038/s41598-017-12700-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 09/13/2017] [Indexed: 12/11/2022] Open
Abstract
The use of entomopathogenic fungi for biocontrol of plant pests is recently receiving an increased interest due to the need of reducing the impact of agricultural practices on the environment. Biocontrol efficacy could be improved by co-inoculation of different microorganisms. However, interactions between the fungal species can trigger or depress the biocontrol activity. Co-inoculation of two entomopathogenic fungi (Beauveria bassiana and B. brongniartii) was performed in vitro to evaluate the effects of their joint behaviour on a range of different carbon sources in comparison to single inoculation. The two species showed a very different metabolic profile by Phenotype MicroArrayTM. B. bassiana showed a broader metabolism than B. brongniartii on a range of substrates. B. brongniartii showed a greater specificity in substrate utilization. Several carbon sources (L-Asparagine, L-Aspartic Acid, L- Glutamic Acid, m- Erythritol, D-Melezitose, D-Sorbitol) triggered the fungal metabolism in the co-inoculum. SSR markers and Real Time qPCR analysis showed that different substrates promoted either the growth of one or the other species, suggesting a form of interaction between the two fungi, related to their different ecological niches. The methodological approach that combines Phenotype MicroArrayTM and SSR genotyping appeared useful to assess the performance and potential competition of co-inoculated entomopathogenic fungi.
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28
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Li W, Xiong P, Zheng W, Zhu X, She Z, Ding W, Li C. Identification and Antifungal Activity of Compounds from the Mangrove Endophytic Fungus Aspergillus clavatus R7. Mar Drugs 2017; 15:md15080259. [PMID: 28825634 PMCID: PMC5577613 DOI: 10.3390/md15080259] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 08/17/2017] [Indexed: 11/24/2022] Open
Abstract
Two new coumarin derivatives, 4,4′-dimethoxy-5,5′-dimethyl-7,7′-oxydicoumarin (1), 7-(γ,γ-dimethylallyloxy)-5-methoxy-4-methylcoumarin (2), a new chromone derivative, (S)-5-hydroxy-2,6-dimethyl-4H-furo[3,4-g]benzopyran-4,8(6H)-dione (5), and a new sterone derivative, 24-hydroxylergosta-4,6,8(14),22-tetraen-3-one (6), along with two known bicoumarins, kotanin (3) and orlandin (4), were isolated from an endophytic fungus Aspergillusclavatus (collection No. R7), isolated from the root of Myoporum bontioides collected from Leizhou Peninsula, China. Their structures were elucidated using 1D- and 2D- NMR spectroscopy, and HRESIMS. The absolute configuration of compound 5 was determined by comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. Compound 6 significantly inhibited the plant pathogenic fungi Fusarium oxysporum, Colletotrichum musae and Penicillium italicum, compound 5 significantly inhibited Colletotrichum musae, and compounds 1, 3 and 4 greatly inhibited Fusarium oxysporum, showing the antifungal activities higher than those of the positive control, triadimefon.
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Affiliation(s)
- Wensheng Li
- College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China.
| | - Ping Xiong
- College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China.
| | - Wenxu Zheng
- College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China.
| | - Xinwei Zhu
- College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China.
| | - Zhigang She
- School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
| | - Weijia Ding
- College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China.
| | - Chunyuan Li
- College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China.
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29
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Luo F, Zhong Z, Liu L, Igarashi Y, Xie D, Li N. Metabolomic differential analysis of interspecific interactions among white rot fungi Trametes versicolor, Dichomitus squalens and Pleurotus ostreatus. Sci Rep 2017; 7:5265. [PMID: 28706236 PMCID: PMC5509712 DOI: 10.1038/s41598-017-05669-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 06/01/2017] [Indexed: 11/25/2022] Open
Abstract
Interspecific fungal antagonism occurred commonly in the interaction zone of different white rot fungi. This competitive interaction could markedly influence the metabolic pathway of intracellular metabolites, which was associated with the fungal morphology change and growth restriction. So far, it remains unknown on intracellular metabolite regulation during fungal competitive interaction. Herein, we performed the metabolomic analysis of the in vivo metabolite changes during competitive interaction between each two of the three white rot fungi Trametes versicolor, Pleurotus ostreatus and Dichomitus squalens and identified differential metabolites in the interaction zone compared to each two isolates. Many metabolites in the carnitine, lipid, ethylene and trehalose metabolic pathways were significantly up-regulated. These metabolic pathways are all involved in defensive response to abiotic and/or biotic stressful condition.
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Affiliation(s)
- Feng Luo
- Research Center of Bioenergy and Bioremediation, College of Resources and Environment, Southwest University, Beibei, Chongqing, 400715, People's Republic of China
| | - Zixuan Zhong
- Research Center of Bioenergy and Bioremediation, College of Resources and Environment, Southwest University, Beibei, Chongqing, 400715, People's Republic of China
| | - Li Liu
- Research Center of Bioenergy and Bioremediation, College of Resources and Environment, Southwest University, Beibei, Chongqing, 400715, People's Republic of China
| | - Yasuo Igarashi
- Research Center of Bioenergy and Bioremediation, College of Resources and Environment, Southwest University, Beibei, Chongqing, 400715, People's Republic of China
| | - Deti Xie
- Research Center of Bioenergy and Bioremediation, College of Resources and Environment, Southwest University, Beibei, Chongqing, 400715, People's Republic of China
| | - Nannan Li
- Research Center of Bioenergy and Bioremediation, College of Resources and Environment, Southwest University, Beibei, Chongqing, 400715, People's Republic of China.
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30
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Paulussen C, Hallsworth JE, Álvarez‐Pérez S, Nierman WC, Hamill PG, Blain D, Rediers H, Lievens B. Ecology of aspergillosis: insights into the pathogenic potency of Aspergillus fumigatus and some other Aspergillus species. Microb Biotechnol 2017; 10:296-322. [PMID: 27273822 PMCID: PMC5328810 DOI: 10.1111/1751-7915.12367] [Citation(s) in RCA: 179] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 04/08/2016] [Accepted: 04/18/2016] [Indexed: 01/26/2023] Open
Abstract
Fungi of the genus Aspergillus are widespread in the environment. Some Aspergillus species, most commonly Aspergillus fumigatus, may lead to a variety of allergic reactions and life-threatening systemic infections in humans. Invasive aspergillosis occurs primarily in patients with severe immunodeficiency, and has dramatically increased in recent years. There are several factors at play that contribute to aspergillosis, including both fungus and host-related factors such as strain virulence and host pulmonary structure/immune status, respectively. The environmental tenacity of Aspergilllus, its dominance in diverse microbial communities/habitats, and its ability to navigate the ecophysiological and biophysical challenges of host infection are attributable, in large part, to a robust stress-tolerance biology and exceptional capacity to generate cell-available energy. Aspects of its stress metabolism, ecology, interactions with diverse animal hosts, clinical presentations and treatment regimens have been well-studied over the past years. Here, we synthesize these findings in relation to the way in which some Aspergillus species have become successful opportunistic pathogens of human- and other animal hosts. We focus on the biophysical capabilities of Aspergillus pathogens, key aspects of their ecophysiology and the flexibility to undergo a sexual cycle or form cryptic species. Additionally, recent advances in diagnosis of the disease are discussed as well as implications in relation to questions that have yet to be resolved.
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Affiliation(s)
- Caroline Paulussen
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM)Department of Microbial and Molecular Systems (M2S)KU LeuvenCampus De NayerSint‐Katelijne‐WaverB‐2860Belgium
| | - John E. Hallsworth
- Institute for Global Food SecuritySchool of Biological SciencesMedical Biology CentreQueen's University BelfastBelfastBT9 7BLUK
| | - Sergio Álvarez‐Pérez
- Faculty of Veterinary MedicineDepartment of Animal HealthUniversidad Complutense de MadridMadridE‐28040Spain
| | | | - Philip G. Hamill
- Institute for Global Food SecuritySchool of Biological SciencesMedical Biology CentreQueen's University BelfastBelfastBT9 7BLUK
| | - David Blain
- Institute for Global Food SecuritySchool of Biological SciencesMedical Biology CentreQueen's University BelfastBelfastBT9 7BLUK
| | - Hans Rediers
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM)Department of Microbial and Molecular Systems (M2S)KU LeuvenCampus De NayerSint‐Katelijne‐WaverB‐2860Belgium
| | - Bart Lievens
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM)Department of Microbial and Molecular Systems (M2S)KU LeuvenCampus De NayerSint‐Katelijne‐WaverB‐2860Belgium
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Regulation of Secondary Metabolism by the Velvet Complex Is Temperature-Responsive in Aspergillus. G3-GENES GENOMES GENETICS 2016; 6:4023-4033. [PMID: 27694115 PMCID: PMC5144971 DOI: 10.1534/g3.116.033084] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Sensing and responding to environmental cues is critical to the lifestyle of filamentous fungi. How environmental variation influences fungi to produce a wide diversity of ecologically important secondary metabolites (SMs) is not well understood. To address this question, we first examined changes in global gene expression of the opportunistic human pathogen, Aspergillus fumigatus, after exposure to different temperature conditions. We found that 11 of the 37 SM gene clusters in A. fumigatus were expressed at higher levels at 30° than at 37°. We next investigated the role of the light-responsive Velvet complex in environment-dependent gene expression by examining temperature-dependent transcription profiles in the absence of two key members of the Velvet protein complex, VeA and LaeA. We found that the 11 temperature-regulated SM gene clusters required VeA at 37° and LaeA at both 30 and 37° for wild-type levels of expression. Interestingly, four SM gene clusters were regulated by VeA at 37° but not at 30°, and two additional ones were regulated by VeA at both temperatures but were substantially less so at 30°, indicating that the role of VeA and, more generally of the Velvet complex, in the regulation of certain SM gene clusters is temperature-dependent. Our findings support the hypothesis that fungal secondary metabolism is regulated by an intertwined network of transcriptional regulators responsive to multiple environmental factors.
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Chatterjee S, Kuang Y, Splivallo R, Chatterjee P, Karlovsky P. Interactions among filamentous fungi Aspergillus niger, Fusarium verticillioides and Clonostachys rosea: fungal biomass, diversity of secreted metabolites and fumonisin production. BMC Microbiol 2016; 16:83. [PMID: 27165654 PMCID: PMC4862089 DOI: 10.1186/s12866-016-0698-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 04/28/2016] [Indexed: 11/10/2022] Open
Abstract
Background Interactions among fungi colonizing dead organic matter involve exploitation competition and interference competition. Major mechanism of interference competition is antibiosis caused by secreted secondary metabolites. The effect of competition on secondary metabolite production by fungi is however poorly understood. Fungal biomass was rarely monitored in interaction studies; it is not known whether dominance in pairwise interactions follows congruent patterns. Results Pairwise interactions of three fungal species with different life styles were studied. The saprophyte Aspergillus niger (A.n.), the plant pathogen Fusarium verticillioides (F.v.), and the mycoparasite Clonostachys rosea (C.r.) were grown in single and dual cultures in minimal medium with asparagine as nitrogen source. Competitive fitness shifted with time: in dual C.r./F.v. cultures after 10 d F.v. grew well while C.r. was suppressed; after 20 d C.r. recovered while F.v. became suppressed; and after 30 d most F.v. was destroyed. At certain time points fungal competitive fitness exhibited a rock–paper–scissors pattern: F.v. > A.n., A.n. > C.r., and C.r. > F.v. Most metabolites secreted to the medium at early stages in single and dual cultures were not found at later times. Many metabolites occurring in supernatants of single cultures were suppressed in dual cultures and many new metabolites not occurring in single cultures were found in dual cultures. A. niger showed the greatest ability to suppress the accumulation of metabolites produced by the other fungi. A. niger was also the species with the largest capacity of transforming metabolites produced by other fungi. Fumonisin production by F. verticillioides was suppressed in co-cultures with C. rosea but fumonisin B1 was not degraded by C. rosea nor did it affect the growth of C. rosea up to a concentration of 160 μg/ml. Conclusions Competitive fitness in pairwise interactions among fungi is incongruent, indicating that species-specific factors and/or effects are involved. Many metabolites secreted by fungi are catabolized by their producers at later growth stages. Diversity of metabolites accumulating in the medium is stimulated by fungus/fungus interactions. C. rosea suppresses the synthesis of fumonisins by F. verticillioides but does not degrade fumonisins. Electronic supplementary material The online version of this article (doi:10.1186/s12866-016-0698-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Subhankar Chatterjee
- Molecular Phytopathology and Mycotoxin Research, Georg-August-University Göttingen, Grisebachstrasse 6, 37077, Göttingen, Germany
| | - Yi Kuang
- Molecular Phytopathology and Mycotoxin Research, Georg-August-University Göttingen, Grisebachstrasse 6, 37077, Göttingen, Germany
| | - Richard Splivallo
- Molecular Phytopathology and Mycotoxin Research, Georg-August-University Göttingen, Grisebachstrasse 6, 37077, Göttingen, Germany
| | - Paramita Chatterjee
- Molecular Phytopathology and Mycotoxin Research, Georg-August-University Göttingen, Grisebachstrasse 6, 37077, Göttingen, Germany
| | - Petr Karlovsky
- Molecular Phytopathology and Mycotoxin Research, Georg-August-University Göttingen, Grisebachstrasse 6, 37077, Göttingen, Germany.
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rtfA, a putative RNA-Pol II transcription elongation factor gene, is necessary for normal morphological and chemical development in Aspergillus flavus. Appl Microbiol Biotechnol 2016; 100:5029-41. [PMID: 27020290 DOI: 10.1007/s00253-016-7418-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 02/22/2016] [Accepted: 02/24/2016] [Indexed: 01/05/2023]
Abstract
The filamentous fungus Aspergillus flavus is an agriculturally important opportunistic plant pathogen that produces potent carcinogenic compounds called aflatoxins. We identified the A. flavus rtfA gene, the ortholog of rtf1 in Saccharomyces cerevisiae and rtfA in Aspergillus nidulans. Interestingly, rtfA has multiple cellular roles in this mycotoxin-producing fungus. In this study, we show that rtfA regulates conidiation. The rtfA deletion mutant presented smaller conidiophores with significantly reduced conidial production compared to the wild-type strain. The absence of rtfA also resulted in a significant decrease or lack of sclerotial production under conditions that allowed abundant production of these resistance structures in the wild type. Importantly, the deletion of rtfA notably reduced the production of aflatoxin B1, indicating that rtfA is a regulator of mycotoxin biosynthesis in A. flavus. In addition, the deletion rtfA also altered the production of several unknown secondary metabolites indicating a broader regulatory scope. Furthermore, our study revealed that rtfA controls the expression of the global regulators veA and laeA, which further influence morphogenesis and secondary metabolism in A. flavus.
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Resistance is not futile: gliotoxin biosynthesis, functionality and utility. Trends Microbiol 2015; 23:419-28. [PMID: 25766143 DOI: 10.1016/j.tim.2015.02.005] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 02/02/2015] [Accepted: 02/17/2015] [Indexed: 12/27/2022]
Abstract
Gliotoxin biosynthesis is encoded by the gli gene cluster in Aspergillus fumigatus. The biosynthesis of gliotoxin is influenced by a suite of transcriptionally-active regulatory proteins and a bis-thiomethyltransferase. A self-protection system against gliotoxin is present in A. fumigatus. Several additional metabolites are also produced via the gliotoxin biosynthetic pathway. Moreover, the biosynthesis of unrelated natural products appears to be influenced either by gliotoxin or by the activity of specific reactions within the biosynthetic pathway. The activity of gliotoxin against animal cells and fungi, often mediated by interference with redox homeostasis or protein modification, is revealing new metabolic interactions within eukaryotic systems. Nature has provided a most useful natural product with which to reveal some of its many molecular secrets.
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Lim FY, Keller NP. Spatial and temporal control of fungal natural product synthesis. Nat Prod Rep 2014; 31:1277-86. [PMID: 25142354 PMCID: PMC4162804 DOI: 10.1039/c4np00083h] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Despite their oftentimes-elusive ecological role, fungal natural products have, for better or worse, impacted our daily lives tremendously owing to their diverse and potent bioactive properties. This Janus-faced nature of fungal natural products inevitably ushered in a field of research dedicated towards understanding the ecology, organisms, genes, enzymes, and biosynthetic pathways that give rise to this arsenal of diverse and complex chemistry. Ongoing research in fungal secondary metabolism has not only increased our appreciation for fungal natural products as an asset but also sheds light on the pivotal role that these once-regarded "metabolic wastes" play in fungal biology, defense, and stress response in addition to their potential contributions towards human mycoses. Full orchestration of secondary metabolism requires not only the seamless coordination between temporal and spatial control of SM-associated machineries (e.g. enzymes, cofactors, intermediates, and end-products) but also integration of these machineries into primary metabolic processes and established cellular mechanisms. An intriguing, but little known aspect of microbial natural product synthesis lies in the spatial organization of both pathway intermediates and enzymes responsible for the production of these compounds. In this highlight, we summarize some major breakthroughs in understanding the genes and regulation of fungal natural product synthesis and introduce the current state of knowledge on the spatial and temporal control of fungal natural product synthesis.
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Affiliation(s)
- Fang Yun Lim
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, U.S.A
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, U.S.A.,Corresponding author Professor Nancy P. Keller, Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, 1550 Linden Drive, Madison WI, U.S.A., Tel: (608)-262-9795; Fax: (608)-262-8418;
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Bertrand S, Bohni N, Schnee S, Schumpp O, Gindro K, Wolfender JL. Metabolite induction via microorganism co-culture: a potential way to enhance chemical diversity for drug discovery. Biotechnol Adv 2014; 32:1180-204. [PMID: 24651031 DOI: 10.1016/j.biotechadv.2014.03.001] [Citation(s) in RCA: 289] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 02/28/2014] [Accepted: 03/03/2014] [Indexed: 02/08/2023]
Abstract
Microorganisms have a long track record as important sources of novel bioactive natural products, particularly in the field of drug discovery. While microbes have been shown to biosynthesize a wide array of molecules, recent advances in genome sequencing have revealed that such organisms have the potential to yield even more structurally diverse secondary metabolites. Thus, many microbial gene clusters may be silent under standard laboratory growth conditions. In the last ten years, several methods have been developed to aid in the activation of these cryptic biosynthetic pathways. In addition to the techniques that demand prior knowledge of the genome sequences of the studied microorganisms, several genome sequence-independent tools have been developed. One of these approaches is microorganism co-culture, involving the cultivation of two or more microorganisms in the same confined environment. Microorganism co-culture is inspired by the natural microbe communities that are omnipresent in nature. Within these communities, microbes interact through signaling or defense molecules. Such compounds, produced dynamically, are of potential interest as new leads for drug discovery. Microorganism co-culture can be achieved in either solid or liquid media and has recently been used increasingly extensively to study natural interactions and discover new bioactive metabolites. Because of the complexity of microbial extracts, advanced analytical methods (e.g., mass spectrometry methods and metabolomics) are key for the successful detection and identification of co-culture-induced metabolites. This review focuses on co-culture studies that aim to increase the diversity of metabolites obtained from microbes. The various strategies are summarized with a special emphasis on the multiple methods of performing co-culture experiments. The analytical approaches for studying these interaction phenomena are discussed, and the chemical diversity and biological activity observed among the induced metabolites are described.
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Affiliation(s)
- Samuel Bertrand
- School of Pharmaceutical Sciences, EPGL, University of Geneva, University of Lausanne, quai Ernest-Ansermet 30, CH-1211 Geneva 4, Switzerland; Groupe Mer, Molécules, Santé-EA 2160, Faculté des Sciences pharmaceutiques et biologiques, Université de Nantes, 9 rue Bias, BP 53508, F-44035 Nantes Cedex 01, France
| | - Nadine Bohni
- School of Pharmaceutical Sciences, EPGL, University of Geneva, University of Lausanne, quai Ernest-Ansermet 30, CH-1211 Geneva 4, Switzerland
| | - Sylvain Schnee
- Mycology and Biotechnology group, Institute for Plant Production Sciences IPS, Agroscope, Route de Duillier 50, P.O. Box 1012, 1260 Nyon, Switzerland
| | - Olivier Schumpp
- Mycology and Biotechnology group, Institute for Plant Production Sciences IPS, Agroscope, Route de Duillier 50, P.O. Box 1012, 1260 Nyon, Switzerland
| | - Katia Gindro
- Mycology and Biotechnology group, Institute for Plant Production Sciences IPS, Agroscope, Route de Duillier 50, P.O. Box 1012, 1260 Nyon, Switzerland
| | - Jean-Luc Wolfender
- School of Pharmaceutical Sciences, EPGL, University of Geneva, University of Lausanne, quai Ernest-Ansermet 30, CH-1211 Geneva 4, Switzerland.
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Breitling R, Ceniceros A, Jankevics A, Takano E. Metabolomics for secondary metabolite research. Metabolites 2013; 3:1076-83. [PMID: 24958266 PMCID: PMC3937839 DOI: 10.3390/metabo3041076] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 10/25/2013] [Accepted: 11/01/2013] [Indexed: 01/26/2023] Open
Abstract
Metabolomics, the global characterization of metabolite profiles, is becoming an increasingly powerful tool for research on secondary metabolite discovery and production. In this review we discuss examples of recent technological advances and biological applications of metabolomics in the search for chemical novelty and the engineered production of bioactive secondary metabolites.
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Affiliation(s)
- Rainer Breitling
- Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.
| | - Ana Ceniceros
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborg 7, Groningen 9747 AG, The Netherlands.
| | - Andris Jankevics
- Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.
| | - Eriko Takano
- Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.
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38
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Mehl HL, Cotty PJ. Nutrient environments influence competition among Aspergillus flavus genotypes. Appl Environ Microbiol 2013; 79:1473-80. [PMID: 23263958 PMCID: PMC3591962 DOI: 10.1128/aem.02970-12] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 12/13/2012] [Indexed: 12/25/2022] Open
Abstract
The population dynamics of Aspergillus flavus, shaped in part by intraspecific competition, influence the likelihood and severity of crop aflatoxin contamination. Competition for nutrients may be one factor modulating intraspecific interactions, but the influences of specific types and concentrations of nutrients on competition between genotypes of A. flavus have not been investigated. Competition between paired A. flavus isolates on agar media was affected by varying concentrations of carbon (sucrose or asparagine) and nitrogen (nitrate or asparagine). Cocultivated isolate percentages from conidia and agar-embedded mycelia were quantified by measurements of isolate-specific single-nucleotide polymorphisms with quantitative pyrosequencing. Compositions and concentrations of nutrients influenced conidiation resulting from cocultivation, but the percentages of total conidia from each competing isolate were not predicted by sporulation of isolates grown individually. Success during sporulation did not reflect the outcomes of competition during mycelial growth, and the extents to which isolate percentages from conidia and mycelia differed varied among both isolate pairs and media. Whether varying concentrations of sucrose, nitrate, or asparagine increased, decreased, or had no influence on competitive ability was isolate dependent. Different responses of A. flavus isolates to nutrient variability suggest genotypes are adapted to different nutrient environments that have the potential to influence A. flavus population structure and the epidemiology of aflatoxin contamination.
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Affiliation(s)
- Hillary L. Mehl
- School of Plant Sciences, University of Arizona, Tucson, Arizona, USA
| | - Peter J. Cotty
- School of Plant Sciences, University of Arizona, Tucson, Arizona, USA
- Agricultural Research Service, U.S. Department of Agriculture, Tucson, Arizona, USA
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Abstract
Fungi produce a multitude of low-molecular-mass compounds known as secondary metabolites, which have roles in a range of cellular processes such as transcription, development and intercellular communication. In addition, many of these compounds now have important applications, for instance, as antibiotics or immunosuppressants. Genome mining efforts indicate that the capability of fungi to produce secondary metabolites has been substantially underestimated because many of the fungal secondary metabolite biosynthesis gene clusters are silent under standard cultivation conditions. In this Review, I describe our current understanding of the regulatory elements that modulate the transcription of genes involved in secondary metabolism. I also discuss how an improved knowledge of these regulatory elements will ultimately lead to a better understanding of the physiological and ecological functions of these important compounds and will pave the way for a novel avenue to drug discovery through targeted activation of silent gene clusters.
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40
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Gibbons JG, Rokas A. The function and evolution of the Aspergillus genome. Trends Microbiol 2012; 21:14-22. [PMID: 23084572 DOI: 10.1016/j.tim.2012.09.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Revised: 09/20/2012] [Accepted: 09/24/2012] [Indexed: 10/27/2022]
Abstract
Species in the filamentous fungal genus Aspergillus display a wide diversity of lifestyles and are of great importance to humans. The decoding of genome sequences from a dozen species that vary widely in their degree of evolutionary affinity has galvanized studies of the function and evolution of the Aspergillus genome in clinical, industrial, and agricultural environments. Here, we synthesize recent key findings that shed light on the architecture of the Aspergillus genome, on the molecular foundations of the genus' astounding dexterity and diversity in secondary metabolism, and on the genetic underpinnings of virulence in Aspergillus fumigatus, one of the most lethal fungal pathogens. Many of these insights dramatically expand our knowledge of fungal and microbial eukaryote genome evolution and function and argue that Aspergillus constitutes a superb model clade for the study of functional and comparative genomics.
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Affiliation(s)
- John G Gibbons
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
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Carberry S, Molloy E, Hammel S, O’Keeffe G, Jones GW, Kavanagh K, Doyle S. Gliotoxin effects on fungal growth: Mechanisms and exploitation. Fungal Genet Biol 2012; 49:302-12. [DOI: 10.1016/j.fgb.2012.02.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 02/09/2012] [Accepted: 02/10/2012] [Indexed: 10/28/2022]
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Lim FY, Sanchez JF, Wang CC, Keller NP. Toward awakening cryptic secondary metabolite gene clusters in filamentous fungi. Methods Enzymol 2012; 517:303-24. [PMID: 23084945 PMCID: PMC3703436 DOI: 10.1016/b978-0-12-404634-4.00015-2] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Mining for novel natural compounds is of eminent importance owing to the continuous need for new pharmaceuticals. Filamentous fungi are historically known to harbor the genetic capacity for an arsenal of natural compounds, both beneficial and detrimental to humans. The majority of these metabolites are still cryptic or silent under standard laboratory culture conditions. Mining for these cryptic natural products can be an excellent source for identifying new compound classes. Capitalizing on the current knowledge on how secondary metabolite gene clusters are regulated has allowed the research community to unlock many hidden fungal treasures, as described in this chapter.
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Affiliation(s)
- Fang Yun Lim
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin, USA
| | - James F. Sanchez
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, School of Pharmacy, Los Angeles, California, USA
| | - Clay C.C. Wang
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, School of Pharmacy, Los Angeles, California, USA,Department of Chemistry, University of Southern California, College of Letters, Arts, and Sciences, Los Angeles, California, USA
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin, USA,Corresponding author:
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The role of glutathione S-transferase GliG in gliotoxin biosynthesis in Aspergillus fumigatus. ACTA ACUST UNITED AC 2011; 18:542-52. [PMID: 21513890 DOI: 10.1016/j.chembiol.2010.12.022] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Revised: 12/15/2010] [Accepted: 12/29/2010] [Indexed: 01/29/2023]
Abstract
Gliotoxin, a redox-active metabolite, is produced by the opportunistic fungal pathogen Aspergillus fumigatus, and its biosynthesis is directed by the gli gene cluster. Knowledge of the biosynthetic pathway to gliotoxin, which contains a disulfide bridge of unknown origin, is limited, although L-Phe and L-Ser are known biosynthetic precursors. Deletion of gliG from the gli cluster, herein functionally confirmed as a glutathione S-transferase, results in abrogation of gliotoxin biosynthesis and accumulation of 6-benzyl-6-hydroxy-1-methoxy-3-methylenepiperazine-2,5-dione. This putative shunt metabolite from the gliotoxin biosynthetic pathway contains an intriguing hydroxyl group at C-6, consistent with a gliotoxin biosynthetic pathway involving thiolation via addition of the glutathione thiol group to a reactive acyl imine intermediate. Complementation of gliG restored gliotoxin production and, unlike gliT, gliG was found not to be involved in fungal self-protection against gliotoxin.
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Yin W, Keller NP. Transcriptional regulatory elements in fungal secondary metabolism. J Microbiol 2011; 49:329-39. [PMID: 21717315 DOI: 10.1007/s12275-011-1009-1] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Accepted: 03/15/2011] [Indexed: 01/19/2023]
Abstract
Filamentous fungi produce a variety of secondary metabolites of diverse beneficial and detrimental activities to humankind. The genes required for a given secondary metabolite are typically arranged in a gene cluster. There is considerable evidence that secondary metabolite gene regulation is, in part, by transcriptional control through hierarchical levels of transcriptional regulatory elements involved in secondary metabolite cluster regulation. Identification of elements regulating secondary metabolism could potentially provide a means of increasing production of beneficial metabolites, decreasing production of detrimental metabolites, aid in the identification of 'silent' natural products and also contribute to a broader understanding of molecular mechanisms by which secondary metabolites are produced. This review summarizes regulation of secondary metabolism associated with transcriptional regulatory elements from a broad view as well as the tremendous advances in discovery of cryptic or novel secondary metabolites by genomic mining.
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Affiliation(s)
- Wenbing Yin
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, USA
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45
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Giles SS, Soukup AA, Lauer C, Shaaban M, Lin A, Oakley BR, Wang CCC, Keller NP. Cryptic Aspergillus nidulans antimicrobials. Appl Environ Microbiol 2011; 77:3669-75. [PMID: 21478304 PMCID: PMC3127626 DOI: 10.1128/aem.02000-10] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Accepted: 03/16/2011] [Indexed: 01/15/2023] Open
Abstract
Secondary metabolite (SM) production by fungi is hypothesized to provide some fitness attribute for the producing organisms. However, most SM clusters are "silent" when fungi are grown in traditional laboratory settings, and it is difficult to ascertain any function or activity of these SM cluster products. Recently, the creation of a chromatin remodeling mutant in Aspergillus nidulans induced activation of several cryptic SM gene clusters. Systematic testing of nine purified metabolites from this mutant identified an emodin derivate with efficacy against both human fungal pathogens (inhibiting both spore germination and hyphal growth) and several bacteria. The ability of catalase to diminish this antimicrobial activity implicates reactive oxygen species generation, specifically, the generation of hydrogen peroxide, as the mechanism of emodin hydroxyl activity.
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Affiliation(s)
- Steve S. Giles
- Department of Medical Microbiology and Immunology, University of Wisconsin—Madison, Madison, Wisconsin
| | | | - Carrie Lauer
- Department of Medical Microbiology and Immunology, University of Wisconsin—Madison, Madison, Wisconsin
| | - Mona Shaaban
- Department of Medical Microbiology and Immunology, University of Wisconsin—Madison, Madison, Wisconsin
- Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| | - Alexander Lin
- Department of Pharmacology and Pharmaceutical Sciences
| | - Berl R. Oakley
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas
| | - Clay C. C. Wang
- Department of Pharmacology and Pharmaceutical Sciences
- Department of Chemistry, University of Southern California, 1985 Zonal Avenue, Los Angeles, California 90033
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin—Madison, Madison, Wisconsin
- Department of Bacteriology, University of Wisconsin—Madison, Madison, Wisconsin
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Abstract
Some fungi cause disease in humans and plants, while others have demonstrable potential for the control of insect pests. In addition, fungi are also a rich reservoir of therapeutic metabolites and industrially useful enzymes. Detailed analysis of fungal biochemistry is now enabled by multiple technologies including protein mass spectrometry, genome and transcriptome sequencing and advances in bioinformatics. Yet, the assignment of function to fungal proteins, encoded either by in silico annotated, or unannotated genes, remains problematic. The purpose of this review is to describe the strategies used by many researchers to reveal protein function in fungi, and more importantly, to consolidate the nomenclature of 'unknown function protein' as opposed to 'hypothetical protein' - once any protein has been identified by protein mass spectrometry. A combination of approaches including comparative proteomics, pathogen-induced protein expression and immunoproteomics are outlined, which, when used in combination with a variety of other techniques (e.g. functional genomics, microarray analysis, immunochemical and infection model systems), appear to yield comprehensive and definitive information on protein function in fungi. The relative advantages of proteomic, as opposed to transcriptomic-only, analyses are also described. In the future, combined high-throughput, quantitative proteomics, allied to transcriptomic sequencing, are set to reveal much about protein function in fungi.
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Affiliation(s)
- Sean Doyle
- Department of Biology and National Institute for Cellular Biotechnology, National University of Ireland, Maynooth, Co. Kildare, Ireland.
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Brakhage AA, Schroeckh V. Fungal secondary metabolites – Strategies to activate silent gene clusters. Fungal Genet Biol 2011; 48:15-22. [DOI: 10.1016/j.fgb.2010.04.004] [Citation(s) in RCA: 518] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Revised: 04/12/2010] [Accepted: 04/21/2010] [Indexed: 12/22/2022]
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48
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Schrettl M, Carberry S, Kavanagh K, Haas H, Jones GW, O'Brien J, Nolan A, Stephens J, Fenelon O, Doyle S. Self-protection against gliotoxin--a component of the gliotoxin biosynthetic cluster, GliT, completely protects Aspergillus fumigatus against exogenous gliotoxin. PLoS Pathog 2010; 6:e1000952. [PMID: 20548963 PMCID: PMC2883607 DOI: 10.1371/journal.ppat.1000952] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Accepted: 05/12/2010] [Indexed: 11/29/2022] Open
Abstract
Gliotoxin, and other related molecules, are encoded by multi-gene clusters and biosynthesized by fungi using non-ribosomal biosynthetic mechanisms. Almost universally described in terms of its toxicity towards mammalian cells, gliotoxin has come to be considered as a component of the virulence arsenal of Aspergillus fumigatus. Here we show that deletion of a single gene, gliT, in the gliotoxin biosynthetic cluster of two A. fumigatus strains, rendered the organism highly sensitive to exogenous gliotoxin and completely disrupted gliotoxin secretion. Addition of glutathione to both A. fumigatus ΔgliT strains relieved gliotoxin inhibition. Moreover, expression of gliT appears to be independently regulated compared to all other cluster components and is up-regulated by exogenous gliotoxin presence, at both the transcript and protein level. Upon gliotoxin exposure, gliT is also expressed in A. fumigatus ΔgliZ, which cannot express any other genes in the gliotoxin biosynthetic cluster, indicating that gliT is primarily responsible for protecting this strain against exogenous gliotoxin. GliT exhibits a gliotoxin reductase activity up to 9 µM gliotoxin and appears to prevent irreversible depletion of intracellular glutathione stores by reduction of the oxidized form of gliotoxin. Cross-species resistance to exogenous gliotoxin is acquired by A. nidulans and Saccharomyces cerevisiae, respectively, when transformed with gliT. We hypothesise that the primary role of gliotoxin may be as an antioxidant and that in addition to GliT functionality, gliotoxin secretion may be a component of an auto-protective mechanism, deployed by A. fumigatus to protect itself against this potent biomolecule. The pathogenic fungus Aspergillus fumigatus causes disease in immunocompromised individuals such as cancer patients. The fungus makes a small molecule called gliotoxin which helps A. fumigatus bypass the immune system in ill people, and cause disease. Although a small molecule, gliotoxin biosynthesis is enabled by a complex series of enzymes, one of which is called GliT, in A. fumigatus. Amazingly, nobody has really considered that gliotoxin might be toxic to A. fumigatus itself. Here we show that absence of GliT makes A. fumigatus highly sensitive to added gliotoxin and inhibits fungal growth, both of which can be reversed by restoring GliT. Neither can the fungus make or release its own gliotoxin when GliT is missing. We also show that gliotoxin sensitivity can be totally overcome by adding glutathione, which is an important anti-oxidant within cells. We demonstrate that gliotoxin addition increases the production of GliT, and that GliT breaks the disulphide bond in gliotoxin which may be a step in the pathway for gliotoxin protection or release from A. fumigatus. We conclude that gliotoxin may mainly be involved in protecting A. fumigatus against oxidative stress and that it is an accidental toxin.
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Affiliation(s)
- Markus Schrettl
- Department of Biology and National Institute for Cellular Biotechnology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
- Biocenter-Division of Molecular Biology, Innsbruck Medical University, Innsbruck, Austria
| | - Stephen Carberry
- Department of Biology and National Institute for Cellular Biotechnology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
| | - Kevin Kavanagh
- Department of Biology and National Institute for Cellular Biotechnology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
| | - Hubertus Haas
- Biocenter-Division of Molecular Biology, Innsbruck Medical University, Innsbruck, Austria
| | - Gary W. Jones
- Department of Biology and National Institute for Cellular Biotechnology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
| | - Jennifer O'Brien
- Department of Biology and National Institute for Cellular Biotechnology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
| | - Aine Nolan
- Department of Biology and National Institute for Cellular Biotechnology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
| | - John Stephens
- Department of Chemistry, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
| | - Orla Fenelon
- Department of Chemistry, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
| | - Sean Doyle
- Department of Biology and National Institute for Cellular Biotechnology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
- * E-mail:
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