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Dong X, Zhang T, Wu W, Peng Y, Liu X, Han Y, Chen X, Gao Z, Xia J, Shao Z, Greening C. A vast repertoire of secondary metabolites potentially influences community dynamics and biogeochemical processes in cold seeps. SCIENCE ADVANCES 2024; 10:eadl2281. [PMID: 38669328 PMCID: PMC11051675 DOI: 10.1126/sciadv.adl2281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 03/27/2024] [Indexed: 04/28/2024]
Abstract
In deep-sea cold seeps, microbial communities thrive on the geological seepage of hydrocarbons and inorganic compounds, differing from photosynthetically driven ecosystems. However, their biosynthetic capabilities remain largely unexplored. Here, we analyzed 81 metagenomes, 33 metatranscriptomes, and 7 metabolomes derived from nine different cold seep areas to investigate their secondary metabolites. Cold seep microbiomes encode diverse and abundant biosynthetic gene clusters (BGCs). Most BGCs are affiliated with understudied bacteria and archaea, including key mediators of methane and sulfur cycling. The BGCs encode diverse antimicrobial compounds that potentially shape community dynamics and various metabolites predicted to influence biogeochemical cycling. BGCs from key players are widely distributed and highly expressed, with their abundance and expression levels varying with sediment depth. Sediment metabolomics reveals unique natural products, highlighting uncharted chemical potential and confirming BGC activity in these sediments. Overall, these results demonstrate that cold seep sediments serve as a reservoir of hidden natural products and sheds light on microbial adaptation in chemosynthetically driven ecosystems.
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Affiliation(s)
- Xiyang Dong
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China
| | - Tianxueyu Zhang
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310005, China
| | - Weichao Wu
- Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Science, Shanghai Ocean University, Shanghai 201306, China
| | - Yongyi Peng
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
- School of Marine Sciences, Sun Yat-Sen University, Zhuhai 519082, China
| | - Xinyue Liu
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
| | - Yingchun Han
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
| | - Xiangwei Chen
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
| | - Zhizeng Gao
- School of Marine Sciences, Sun Yat-Sen University, Zhuhai 519082, China
| | - Jinmei Xia
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
| | - Zongze Shao
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
| | - Chris Greening
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
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Kawahara D, Kai K. Disproof of the Structures and Biosynthesis of Ergoynes, Gs-Polyyne-l-Ergothioneine Cycloadducts from Gynuella sunshinyii YC6258. J Org Chem 2024; 89:5715-5725. [PMID: 38593068 DOI: 10.1021/acs.joc.4c00243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
Some bacteria produce "bacterial polyynes" bearing a conjugated C≡C bond that starts with a terminal alkyne. Ergoynes A and B have been reported as sulfur-containing metabolites from Gynuella sunshinyii YC6258. These compounds were thought to be formed by cycloaddition between a bacterial polyyne (named Gs-polyyne) and l-ergothioneine. The biosynthetic gene clusters (BGCs), which may contribute to their synthesis, were present in the YC6258 genome. The biosynthetic origin of Gs-polyyne is interesting considering its rare 2-isopentyl fatty acyl skeleton. Here, the structures and biosynthesis of Gs-polyyne and ergoynes were verified by analytical, chemical, and genetic techniques. In the YC6258 extract, which was prepared considering their instability, Gs-polyyne was detected as a major LC peak, and ergoynes were not detected. The NMR data of the isolated Gs-polyyne contradicted the proposed structure and identified it as the previously reported protegenin A. The expression of Gs-polyyne BGC in Escherichia coli BL21(DE3) also yielded protegenin A. The cyclization between protegenin A and l-ergothioneine did not proceed during sample preparation; a base, such as potassium carbonate, was required. Overall, Gs-polyyne was identified as protegenin A, while ergoynes were determined to be artifacts. This cyclization may provide a derivatization to stabilize polyynes or create new chemical space.
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Affiliation(s)
- Daiki Kawahara
- Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Kenji Kai
- Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
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Eichelberger KR, Paul S, Peters BM, Cassat JE. Candida-bacterial cross-kingdom interactions. Trends Microbiol 2023; 31:1287-1299. [PMID: 37640601 PMCID: PMC10843858 DOI: 10.1016/j.tim.2023.08.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 07/14/2023] [Accepted: 08/02/2023] [Indexed: 08/31/2023]
Abstract
While the fungus Candida albicans is a common colonizer of healthy humans, it is also responsible for mucosal infections and severe invasive disease. Understanding the mechanisms that allow C. albicans to exist as both a benign commensal and as an invasive pathogen have been the focus of numerous studies, and recent findings indicate an important role for cross-kingdom interactions on C. albicans biology. This review highlights how C. albicans-bacteria interactions influence healthy polymicrobial community structure, host immune responses, microbial pathogenesis, and how dysbiosis may lead to C. albicans infection. Finally, we discuss how cross-kingdom interactions represent an opportunity to identify new antivirulence compounds that target fungal infections.
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Affiliation(s)
- Kara R Eichelberger
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Saikat Paul
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Brian M Peters
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, TN, USA; Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, USA
| | - James E Cassat
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Vanderbilt Institute for Infection, Immunology, and Inflammation (VI4), Vanderbilt University Medical Center, Nashville, TN, USA
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Suenaga M, Katayama N, Kitamura K, Kai K. Structures and Biosynthesis of Caryoynencins, Unstable Bacterial Polyynes from Pseudomonas protegens Recombinant Expressing the cayG Gene. J Org Chem 2023; 88:16280-16291. [PMID: 37947517 DOI: 10.1021/acs.joc.3c01789] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Bacteria in certain genera can produce "bacterial polyynes" that contain a conjugated C≡C bond starting from a terminal alkyne. Protegenin A is a derivative of octadecanoic acid that contains an ene-tetrayne moiety. It was discovered in Pseudomonas protegens Cab57 and exhibits strong antioomycete and moderate antifungal activity. By introducing cayG, a cytochrome P450 gene from Burkholderia caryophylli, into P. protegens Cab57, protegenin A was converted into more complex polyynes, caryoynencins A-E. A purification method that minimized the degradation and isomerization of caryoynencins was established. For the first time, as far as we know, the 1H and 13C{1H} NMR signals of caryoynencins were completely assigned by analyzing the NMR data of the isolated compounds and protegenin A enriched with [1-13C]- or [2-13C]-acetate. Through the structural analysis of caryoynencins D/E and bioconversion experiments, we observed that CayG constructs the allyl alcohol moiety of caryoynencins A-C through sequential hydroxylation, dehydration, and hydroxylation. The recombinant strain exhibited a stronger antioomycete activity compared to the wild-type strain. This paper proposes a stable purification and structural determination method for various bacterial polyynes, and P. protegens Cab57 holds promise as an engineering host for the production of biologically active polyynes.
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Affiliation(s)
- Mayuna Suenaga
- Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Naoka Katayama
- Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Kokoro Kitamura
- Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Kenji Kai
- Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
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Zhang J, Tan H. Microbial quorum sensing signaling molecules and their roles in the biosynthesis of natural products. SCIENCE CHINA. LIFE SCIENCES 2023; 66:2429-2432. [PMID: 37389761 DOI: 10.1007/s11427-023-2389-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 06/07/2023] [Indexed: 07/01/2023]
Affiliation(s)
- Jihui Zhang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Huarong Tan
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
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Wein P, Dornblut K, Herkersdorf S, Krüger T, Molloy EM, Brakhage AA, Hoffmeister D, Hertweck C. Bacterial secretion systems contribute to rapid tissue decay in button mushroom soft rot disease. mBio 2023; 14:e0078723. [PMID: 37486262 PMCID: PMC10470514 DOI: 10.1128/mbio.00787-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 06/08/2023] [Indexed: 07/25/2023] Open
Abstract
The soft rot pathogen Janthinobacterium agaricidamnosum causes devastating damage to button mushrooms (Agaricus bisporus), one of the most cultivated and commercially relevant mushrooms. We previously discovered that this pathogen releases the membrane-disrupting lipopeptide jagaricin. This bacterial toxin, however, could not solely explain the rapid decay of mushroom fruiting bodies, indicating that J. agaricidamnosum implements a more sophisticated infection strategy. In this study, we show that secretion systems play a crucial role in soft rot disease. By mining the genome of J. agaricidamnosum, we identified gene clusters encoding a type I (T1SS), a type II (T2SS), a type III (T3SS), and two type VI secretion systems (T6SSs). We targeted the T2SS and T3SS for gene inactivation studies, and subsequent bioassays implicated both in soft rot disease. Furthermore, through a combination of comparative secretome analysis and activity-guided fractionation, we identified a number of secreted lytic enzymes responsible for mushroom damage. Our findings regarding the contribution of secretion systems to the disease process expand the current knowledge of bacterial soft rot pathogens and represent a significant stride toward identifying targets for their disarmament with secretion system inhibitors. IMPORTANCE The button mushroom (Agaricus bisporus) is the most popular edible mushroom in the Western world. However, mushroom crops can fall victim to serious bacterial diseases that are a major threat to the mushroom industry, among them being soft rot disease caused by Janthinobacterium agaricidamnosum. Here, we show that the rapid dissolution of mushroom fruiting bodies after bacterial invasion is due to degradative enzymes and putative effector proteins secreted via the type II secretion system (T2SS) and the type III secretion system (T3SS), respectively. The ability to degrade mushroom tissue is significantly attenuated in secretion-deficient mutants, which establishes that secretion systems are key factors in mushroom soft rot disease. This insight is of both ecological and agricultural relevance by shedding light on the disease processes behind a pathogenic bacterial-fungal interaction which, in turn, serves as a starting point for the development of secretion system inhibitors to control disease progression.
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Affiliation(s)
- Philipp Wein
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
| | - Katharina Dornblut
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
| | - Sebastian Herkersdorf
- Department of Pharmaceutical Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Friedrich Schiller University Jena, Jena, Germany
- Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany
| | - Thomas Krüger
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
| | - Evelyn M. Molloy
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
| | - Axel A. Brakhage
- Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
| | - Dirk Hoffmeister
- Department of Pharmaceutical Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Friedrich Schiller University Jena, Jena, Germany
- Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
- Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany
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Tsumori C, Matsuo S, Murai Y, Kai K. Quorum Sensing-Dependent Invasion of Ralstonia solanacearum into Fusarium oxysporum Chlamydospores. Microbiol Spectr 2023; 11:e0003623. [PMID: 37367297 PMCID: PMC10433826 DOI: 10.1128/spectrum.00036-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 06/02/2023] [Indexed: 06/28/2023] Open
Abstract
Strains of the Ralstonia solanacearum species complex (RSSC), although known as the causative agent of bacterial wilt disease in plants, induce the chlamydospores of many fungal species and invade them through the spores. The lipopeptide ralstonins are the chlamydospore inducers produced by RSSC and are essential for this invasion. However, no mechanistic investigation of this interaction has been conducted. In this study, we report that quorum sensing (QS), which is a bacterial cell-cell communication, is important for RSSC to invade the fungus Fusarium oxysporum (Fo). ΔphcB, a deletion mutant of QS signal synthase, lost the ability to both produce ralstonins and invade Fo chlamydospores. The QS signal methyl 3-hydroxymyristate rescued these disabilities. In contrast, exogenous ralstonin A, while inducing Fo chlamydospores, failed to rescue the invasive ability. Gene-deletion and -complementation experiments revealed that the QS-dependent production of extracellular polysaccharide I (EPS I) is essential for this invasion. The RSSC cells adhered to Fo hyphae and formed biofilms there before inducing chlamydospores. This biofilm formation was not observed in the EPS I- or ralstonin-deficient mutant. Microscopic analysis showed that RSSC infection resulted in the death of Fo chlamydospores. Altogether, we report that the RSSC QS system is important for this lethal endoparasitism. Among the factors regulated by the QS system, ralstonins, EPS I, and biofilm are important parasitic factors. IMPORTANCE Ralstonia solanacearum species complex (RSSC) strains infect both plants and fungi. The phc quorum-sensing (QS) system of RSSC is important for parasitism on plants, because it allows them to invade and proliferate within the hosts by causing appropriate activation of the system at each infection step. In this study, we confirm that ralstonin A is important not only for Fusarium oxysporum (Fo) chlamydospore induction but also for RSSC biofilm formation on Fo hyphae. Extracellular polysaccharide I (EPS I) is also essential for biofilm formation, while the phc QS system controls these factors in terms of production. The present results advocate a new QS-dependent mechanism for the process by which a bacterium invades a fungus.
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Affiliation(s)
- Chiaki Tsumori
- Graduate School of Agriculture, Osaka Metropolitan University, Osaka, Japan
| | - Shoma Matsuo
- Graduate School of Agriculture, Osaka Metropolitan University, Osaka, Japan
| | - Yuta Murai
- Graduate School of Agriculture, Osaka Metropolitan University, Osaka, Japan
| | - Kenji Kai
- Graduate School of Agriculture, Osaka Metropolitan University, Osaka, Japan
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Seibold PS, Lawrinowitz S, Raztsou I, Gressler M, Arndt HD, Stallforth P, Hoffmeister D. Bifurcate evolution of quinone synthetases in basidiomycetes. Fungal Biol Biotechnol 2023; 10:14. [PMID: 37400920 DOI: 10.1186/s40694-023-00162-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 06/14/2023] [Indexed: 07/05/2023] Open
Abstract
BACKGROUND The terphenylquinones represent an ecologically remarkable class of basidiomycete natural products as they serve as central precursors of pigments and compounds that impact on microbial consortia by modulating bacterial biofilms and motility. This study addressed the phylogenetic origin of the quinone synthetases that assemble the key terphenylquinones polyporic acid and atromentin. RESULTS The activity of the Hapalopilus rutilans synthetases HapA1, HapA2 and of Psilocybe cubensis PpaA1 were reconstituted in Aspergilli. Liquid chromatography and mass spectrometry of the culture extracts identified all three enzymes as polyporic acid synthetases. PpaA1 is unique in that it features a C-terminal, yet catalytically inactive dioxygenase domain. Combined with bioinformatics to reconstruct the phylogeny, our results demonstrate that basidiomycete polyporic acid and atromentin synthetases evolved independently, although they share an identical catalytic mechanism and release structurally very closely related products. A targeted amino acid replacement in the substrate binding pocket of the adenylation domains resulted in bifunctional synthetases producing both polyporic acid and atromentin. CONCLUSIONS Our results imply that quinone synthetases evolved twice independently in basidiomycetes, depending on the aromatic α-keto acid substrate. Furthermore, key amino acid residues for substrate specificity were identified and changed which led to a relaxed substrate profile. Therefore, our work lays the foundation for future targeted enzyme engineering.
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Affiliation(s)
- Paula Sophie Seibold
- Institute of Pharmacy, Department Pharmaceutical Microbiology, Friedrich Schiller University Jena, Winzerlaer Strasse 2, 07745, Jena, Germany
- Department Pharmaceutical Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Winzerlaer Strasse 2, 07745, Jena, Germany
| | - Stefanie Lawrinowitz
- Institute of Pharmacy, Department Pharmaceutical Microbiology, Friedrich Schiller University Jena, Winzerlaer Strasse 2, 07745, Jena, Germany
- Department Pharmaceutical Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Winzerlaer Strasse 2, 07745, Jena, Germany
| | - Ihar Raztsou
- Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich-Schiller-Universität Jena, Humboldtstrasse 10, 07743, Jena, Germany
| | - Markus Gressler
- Institute of Pharmacy, Department Pharmaceutical Microbiology, Friedrich Schiller University Jena, Winzerlaer Strasse 2, 07745, Jena, Germany
- Department Pharmaceutical Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Winzerlaer Strasse 2, 07745, Jena, Germany
| | - Hans-Dieter Arndt
- Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich-Schiller-Universität Jena, Humboldtstrasse 10, 07743, Jena, Germany
| | - Pierre Stallforth
- Department Paleobiotechnology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Winzerlaer Strasse 2, 07745, Jena, Germany
| | - Dirk Hoffmeister
- Institute of Pharmacy, Department Pharmaceutical Microbiology, Friedrich Schiller University Jena, Winzerlaer Strasse 2, 07745, Jena, Germany.
- Department Pharmaceutical Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Winzerlaer Strasse 2, 07745, Jena, Germany.
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Ahammed GJ, Shamsy R, Liu A, Chen S. Arbuscular mycorrhizal fungi-induced tolerance to chromium stress in plants. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 327:121597. [PMID: 37031849 DOI: 10.1016/j.envpol.2023.121597] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 02/11/2023] [Accepted: 04/06/2023] [Indexed: 06/19/2023]
Abstract
Chromium (Cr) is one of the toxic elements that harms all forms of life, including plants. Industrial discharges and mining largely contribute to Cr release into the soil environment. Excessive Cr pollution in arable land significantly reduces the yield and quality of important agricultural crops. Therefore, remediation of polluted soil is imperative not only for agricultural sustainability but also for food safety. Arbuscular mycorrhizal fungi (AMF) are widespread soil-borne endophytic fungi that form mutualistic relationships with the vast majority of land plants. In mycorrhizal symbiosis, AMF are largely dependent on the host plant-supplied carbohydrates and lipids, in return, AMF aid the host plants in acquiring water and mineral nutrients, especially phosphorus, nitrogen and sulfur from distant soils, and this distinguishing feature of the two-way exchange of resources is a functional requirement for such mutualism and ecosystem services. In addition to supplying nutrients and water to plants, the AMF symbiosis enhances plant resilience to biotic and abiotic stresses including Cr stress. Studies have revealed vital physiological and molecular mechanisms by which AMF alleviate Cr phytotoxicity and aid plants in nutrient acquisition under Cr stress. Notably, plant Cr tolerance is enhanced by both the direct effects of AMF on Cr stabilization and transformation, and the indirect effects of AMF symbiosis on plant nutrient uptake and physiological regulation. In this article, we summarized the research progress on AMF and associated mechanisms of Cr tolerance in plants. In addition, we reviewed the present understanding of AMF-assisted Cr remediation. Since AMF symbiosis can enhance plant resilience to Cr pollution, AMF may have promising prospects in agricultural production, bioremediation, and ecological restoration in Cr-polluted soils.
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Affiliation(s)
- Golam Jalal Ahammed
- College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang, 471023, PR China; Henan International Joint Laboratory of Stress Resistance Regulation and Safe Production of Protected Vegetables, Luoyang, 471023, PR China; Henan Engineering Technology Research Center for Horticultural Crop Safety and Disease Control, Luoyang, 471023, PR China
| | - Rubya Shamsy
- Microbiology Program, Department of Mathematics & Natural Sciences, Brac University, 66 Mohakhali, Dhaka, 1212, Bangladesh
| | - Airong Liu
- College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang, 471023, PR China.
| | - Shuangchen Chen
- College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang, 471023, PR China; Henan International Joint Laboratory of Stress Resistance Regulation and Safe Production of Protected Vegetables, Luoyang, 471023, PR China; Henan Engineering Technology Research Center for Horticultural Crop Safety and Disease Control, Luoyang, 471023, PR China
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García-Breijo FJ, Molins A, Reig-Armiñana J, Barreno E. The Tripartite Lichen Ricasolia virens: Involvement of Cyanobacteria and Bacteria in Its Morphogenesis. Microorganisms 2023; 11:1517. [PMID: 37375019 DOI: 10.3390/microorganisms11061517] [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: 05/01/2023] [Revised: 05/31/2023] [Accepted: 06/05/2023] [Indexed: 06/29/2023] Open
Abstract
Ricasolia virens is an epiphytic lichen-forming fungus mainly distributed in Western Europe and Macaronesia in well-structured forests with ecological continuity that lack eutrophication. It is considered to be threatened or extinct in many territories in Europe (IUCN). Despite its biological and ecological relevance, studies on this taxon are scarce. The thalli are tripartite, and the mycobiont has a simultaneous symbiotic relationship with cyanobacteria and green microalgae, which represent interesting models to analyse the strategies and adaptations resulting from the interactions of lichen symbionts. The present study was designed to contribute to a better understanding of this taxon, which has shown a clear decline over the last century. The symbionts were identified by molecular analysis. The phycobiont is Symbiochloris reticulata, and the cyanobionts (Nostoc) are embedded in internal cephalodia. Light, transmission electron and low-temperature scanning microscopy techniques were used to investigate the thallus anatomy, ultrastructure of microalgae and ontogeny of pycnidia and cephalodia. The thalli are very similar to its closest relative, Ricasolia quercizans. The cellular ultrastructure of S. reticulata by TEM is provided. Non-photosynthetic bacteria located outside the upper cortex are introduced through migratory channels into the subcortical zone by the splitting of fungal hyphae. Cephalodia were very abundant, but never as external photosymbiodemes.
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Affiliation(s)
- Francisco J García-Breijo
- Departamento de Ecosistemas Agroforestales, ETSIAMN, Universitat Politècnica de València, Camino de Vera s/n, 46022 València, Spain
| | - Arantzazu Molins
- Instituto Cavanilles de Biodiversidad y Biología Evolutiva (ICBiBE), Botánica, Universitat de València, C/Dr. Moliner, 50, 46100 Burjassot, Spain
- Instituto de Investigaciones Agroambientales y de Economía del Agua (INAGEA), Departamento de Biología, Universitat de les Illes Balears (UIB), Ctra. Valldemossa Km.7., 07122 Palma de Malllorca, Spain
| | - José Reig-Armiñana
- Instituto Cavanilles de Biodiversidad y Biología Evolutiva (ICBiBE), Botánica, Universitat de València, C/Dr. Moliner, 50, 46100 Burjassot, Spain
| | - Eva Barreno
- Instituto Cavanilles de Biodiversidad y Biología Evolutiva (ICBiBE), Botánica, Universitat de València, C/Dr. Moliner, 50, 46100 Burjassot, Spain
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11
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González Plaza JJ, Hradecký J. The tropical cookbook: Termite diet and phylogenetics—Over geographical origin—Drive the microbiome and functional genetic structure of nests. Front Microbiol 2023; 14:1089525. [PMID: 36998409 PMCID: PMC10043212 DOI: 10.3389/fmicb.2023.1089525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 02/13/2023] [Indexed: 03/15/2023] Open
Abstract
Termites are key decomposers of dead plant material involved in the organic matter recycling process in warm terrestrial ecosystems. Due to their prominent role as urban pests of timber, research efforts have been directed toward biocontrol strategies aimed to use pathogens in their nest. However, one of the most fascinating aspects of termites is their defense strategies that prevent the growth of detrimental microbiological strains in their nests. One of the controlling factors is the nest allied microbiome. Understanding how allied microbial strains protect termites from pathogen load could provide us with an enhanced repertoire for fighting antimicrobial-resistant strains or mining for genes for bioremediation purposes. However, a necessary first step is to characterize these microbial communities. To gain a deeper understanding of the termite nest microbiome, we used a multi-omics approach for dissecting the nest microbiome in a wide range of termite species. These cover several feeding habits and three geographical locations on two tropical sides of the Atlantic Ocean known to host hyper-diverse communities. Our experimental approach included untargeted volatile metabolomics, targeted evaluation of volatile naphthalene, a taxonomical profile for bacteria and fungi through amplicon sequencing, and further diving into the genetic repertoire through a metagenomic sequencing approach. Naphthalene was present in species belonging to the genera Nasutitermes and Cubitermes. We investigated the apparent differences in terms of bacterial community structure and discovered that feeding habits and phylogenetic relatedness had a greater influence than geographical location. The phylogenetic relatedness among nests' hosts influences primarily bacterial communities, while diet influences fungi. Finally, our metagenomic analysis revealed that the gene content provided both soil-feeding genera with similar functional profiles, while the wood-feeding genus showed a different one. Our results indicate that the nest functional profile is largely influenced by diet and phylogenetic relatedness, irrespective of geographical location.
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Adaptations of Pseudoxylaria towards a comb-associated lifestyle in fungus-farming termite colonies. THE ISME JOURNAL 2023; 17:733-747. [PMID: 36841903 PMCID: PMC10119272 DOI: 10.1038/s41396-023-01374-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 01/12/2023] [Accepted: 01/17/2023] [Indexed: 02/27/2023]
Abstract
Characterizing ancient clades of fungal symbionts is necessary for understanding the evolutionary process underlying symbiosis development. In this study, we investigated a distinct subgeneric taxon of Xylaria (Xylariaceae), named Pseudoxylaria, whose members have solely been isolated from the fungus garden of farming termites. Pseudoxylaria are inconspicuously present in active fungus gardens of termite colonies and only emerge in the form of vegetative stromata, when the fungus comb is no longer attended ("sit and wait" strategy). Insights into the genomic and metabolic consequences of their association, however, have remained sparse. Capitalizing on viable Pseudoxylaria cultures from different termite colonies, we obtained genomes of seven and transcriptomes of two Pseudoxylaria isolates. Using a whole-genome-based comparison with free-living members of the genus Xylaria, we document that the association has been accompanied by significant reductions in genome size, protein-coding gene content, and reduced functional capacities related to oxidative lignin degradation, oxidative stress responses and secondary metabolite production. Functional studies based on growth assays and fungus-fungus co-cultivations, coupled with isotope fractionation analysis, showed that Pseudoxylaria only moderately antagonizes growth of the termite food fungus Termitomyces, and instead extracts nutrients from the food fungus biomass for its own growth. We also uncovered that Pseudoxylaria is still capable of producing structurally unique metabolites, which was exemplified by the isolation of two novel metabolites, and that the natural product repertoire correlated with antimicrobial and insect antifeedant activity.
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Graffius S, Garzón JFG, Zehl M, Pjevac P, Kirkegaard R, Flieder M, Loy A, Rattei T, Ostrovsky A, Zotchev SB. Secondary Metabolite Production Potential in a Microbiome of the Freshwater Sponge Spongilla lacustris. Microbiol Spectr 2023; 11:e0435322. [PMID: 36728429 PMCID: PMC10100984 DOI: 10.1128/spectrum.04353-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 01/17/2023] [Indexed: 02/03/2023] Open
Abstract
Marine and freshwater sponges harbor diverse communities of bacteria with vast potential to produce secondary metabolites that may play an important role in protecting the host from predators and infections. In this work, we initially used cultivation and metagenomics to investigate the microbial community of the freshwater sponge Spongilla lacustris collected in an Austrian lake. Representatives of 41 bacterial genera were isolated from the sponge sample and classified according to their 16S rRNA gene sequences. The genomes of 33 representative isolates and the 20 recovered metagenome-assembled genomes (MAGs) contained in total 306 secondary metabolite biosynthesis gene clusters (BGCs). Comparative 16S rRNA gene and genome analyses showed very little taxon overlap between the recovered isolates and the sponge community as revealed by cultivation-independent methods. Both culture-independent and -dependent analyses suggested high biosynthetic potential of the S. lacustris microbiome, which was confirmed experimentally even at the subspecies level for two Streptomyces isolates. To our knowledge, this is the most thorough description of the secondary metabolite production potential of a freshwater sponge microbiome to date. IMPORTANCE A large body of research is dedicated to marine sponges, filter-feeding animals harboring rich bacterial microbiomes believed to play an important role in protecting the host from predators and infections. Freshwater sponges have received so far much less attention with respect to their microbiomes, members of which may produce bioactive secondary metabolites with potential to be developed into drugs to treat a variety of diseases. In this work, we investigated the potential of bacteria associated with the freshwater sponge Spongilla lacustris to biosynthesize diverse secondary metabolites. Using culture-dependent and -independent methods, we discovered over 300 biosynthetic gene clusters in sponge-associated bacteria and proved production of several compounds by selected isolates using genome mining. Our results illustrate the importance of a complex approach when dealing with microbiomes of multicellular organisms that may contain producers of medically important secondary metabolites.
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Affiliation(s)
- Sophie Graffius
- Department of Pharmaceutical Sciences, Division of Pharmacognosy, University of Vienna, Vienna, Austria
| | | | - Martin Zehl
- Department of Analytical Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria
| | - Petra Pjevac
- Joint Microbiome Facility of the Medical University of Vienna and the University of Vienna, University of Vienna, Vienna, Austria
- Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Rasmus Kirkegaard
- Joint Microbiome Facility of the Medical University of Vienna and the University of Vienna, University of Vienna, Vienna, Austria
- Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Mathias Flieder
- Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- Doctoral School in Microbiology and Environmental Science, University of Vienna, Vienna, Austria
| | - Alexander Loy
- Joint Microbiome Facility of the Medical University of Vienna and the University of Vienna, University of Vienna, Vienna, Austria
- Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Thomas Rattei
- Department of Microbiology and Ecosystem Science, Division of Computational System Biology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- Doctoral School in Microbiology and Environmental Science, University of Vienna, Vienna, Austria
| | - Andrew Ostrovsky
- Department of Palaeontology, Faculty of Earth Sciences, Geography and Astronomy, Geozentrum, University of Vienna, Vienna, Austria
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Sergey B. Zotchev
- Department of Pharmaceutical Sciences, Division of Pharmacognosy, University of Vienna, Vienna, Austria
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Stallforth P, Mittag M, Brakhage AA, Hertweck C, Hellmich UA. Functional modulation of chemical mediators in microbial communities. Trends Biochem Sci 2023; 48:71-81. [PMID: 35981931 DOI: 10.1016/j.tibs.2022.07.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 07/14/2022] [Accepted: 07/20/2022] [Indexed: 12/27/2022]
Abstract
Interactions between microorganisms are often mediated by specialized metabolites. Although the structures and biosynthesis of these compounds may have been elucidated, microbes exist within complex microbiomes and chemical signals can thus also be subject to community-dependent modifications. Increasingly powerful chemical and biological tools allow to shed light on this poorly understood aspect of chemical ecology. We provide an overview of loss-of-function and gain-of-function chemical mediator (CM) modifications within microbial multipartner relationships. Although loss-of-function modifications are abundant in the literature, few gain-of-function modifications have been described despite their important role in microbial interactions. Research in this field holds great potential for our understanding of microbial interactions and may also provide novel tools for targeted interference with microbial signaling.
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Affiliation(s)
- Pierre Stallforth
- Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll Institute, Beutenbergstrasse 11a, 07745 Jena, Germany; Friedrich Schiller University Jena, Faculty of Chemistry and Earth Sciences, Institute of Organic Chemistry and Macromolecular Chemistry, Humboldtstrasse 10, 07743 Jena, Germany.
| | - Maria Mittag
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Axel A Brakhage
- Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll Institute, Beutenbergstrasse 11a, 07745 Jena, Germany; Institute of Microbiology, Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Christian Hertweck
- Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll Institute, Beutenbergstrasse 11a, 07745 Jena, Germany; Institute of Microbiology, Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Ute A Hellmich
- Friedrich Schiller University Jena, Faculty of Chemistry and Earth Sciences, Institute of Organic Chemistry and Macromolecular Chemistry, Humboldtstrasse 10, 07743 Jena, Germany; Centre for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max-von-Laue-Strasse 9, 60438 Frankfurt, Germany.
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15
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Büttner H, Pidot SJ, Scherlach K, Hertweck C. Endofungal bacteria boost anthelminthic host protection with the biosurfactant symbiosin. Chem Sci 2022; 14:103-112. [PMID: 36605741 PMCID: PMC9769094 DOI: 10.1039/d2sc04167g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 11/20/2022] [Indexed: 11/22/2022] Open
Abstract
Effective protection of soil fungi from predators is crucial for their survival in the niche. Thus, fungi have developed efficient defence strategies. We discovered that soil beneficial Mortierella fungi employ a potent cytotoxin (necroxime) against fungivorous nematodes. Interestingly, this anthelminthic agent is produced by bacterial endosymbionts (Candidatus Mycoavidus necroximicus) residing within the fungus. Analysis of the symbiont's genome indicated a rich biosynthetic potential, yet nothing has been known about additional metabolites and their potential synergistic functions. Here we report that two distinct Mortierella endosymbionts produce a novel cyclic lipodepsipeptide (symbiosin), that is clearly of bacterial origin, but has striking similarities to various fungal specialized metabolites. The structure and absolute configuration of symbiosin were fully elucidated. By comparative genomics of symbiosin-positive strains and in silico analyses of the deduced non-ribosomal synthetases, we assigned the (sym) biosynthetic gene cluster and proposed an assembly line model. Bioassays revealed that symbiosin is not only an antibiotic, in particular against mycobacteria, but also exhibits marked synergistic effects with necroxime in anti-nematode tests. By functional analyses and substitution experiments we found that symbiosin is a potent biosurfactant and that this particular property confers a boost in the anthelmintic action, similar to formulations of therapeutics in human medicine. Our findings illustrate that "combination therapies" against parasites already exist in ecological contexts, which may inspire the development of biocontrol agents and therapeutics.
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Affiliation(s)
- Hannah Büttner
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (Leibniz-HKI)Beutenbergstrasse 11a07745 JenaGermany
| | - Sacha J. Pidot
- Department of Microbiology and Immunology, Doherty Institute792 Elizabeth StreetMelbourne3000Australia
| | - Kirstin Scherlach
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (Leibniz-HKI)Beutenbergstrasse 11a07745 JenaGermany
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (Leibniz-HKI)Beutenbergstrasse 11a07745 JenaGermany,Institute of Microbiology, Faculty of Biological Sciences, Friedrich Schiller University Jena07743 JenaGermany
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Solanimycin: Biosynthesis and Distribution of a New Antifungal Antibiotic Regulated by Two Quorum-Sensing Systems. mBio 2022; 13:e0247222. [PMID: 36214559 PMCID: PMC9765074 DOI: 10.1128/mbio.02472-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The increasing emergence of drug-resistant fungal infections has necessitated a search for new compounds capable of combating fungal pathogens of plants, animals, and humans. Microorganisms represent the main source of antibiotics with applicability in agriculture and in the clinic, but many aspects of their metabolic potential remain to be explored. This report describes the discovery and characterization of a new antifungal compound, solanimycin, produced by a hybrid polyketide/nonribosomal peptide (PKS/NRPS) system in Dickeya solani, the enterobacterial pathogen of potato. Solanimycin was active against a broad range of plant-pathogenic fungi of global economic concern and the human pathogen Candida albicans. The genomic cluster responsible for solanimycin production was defined and analyzed to identify the corresponding biosynthetic proteins, which include four multimodular PKS/NRPS proteins and several tailoring enzymes. Antifungal production in D. solani was enhanced in response to experimental conditions found in infected potato tubers and high-density fungal cultures. Solanimycin biosynthesis was cell density dependent in D. solani and was controlled by both the ExpIR acyl-homoserine lactone and Vfm quorum-sensing systems of the bacterial phytopathogen. The expression of the solanimycin cluster was also regulated at the post-transcriptional level, with the regulator RsmA playing a major role. The solanimycin biosynthetic cluster was conserved across phylogenetically distant bacterial genera, and multiple pieces of evidence support that the corresponding gene clusters were acquired by horizontal gene transfer. Given its potent broad-range antifungal properties, this study suggests that solanimycin and related molecules may have potential utility for agricultural and clinical exploitation. IMPORTANCE Fungal infections represent a major clinical, agricultural, and food security threat worldwide, which is accentuated due to the difficult treatment of these infections. Microorganisms represent a prolific source of antibiotics, and current data support that this enormous biosynthetic potential has been scarcely explored. To improve the performance in the discovery of novel antimicrobials, there is a need to diversify the isolation niches for new antibiotic-producing microorganisms as well as to scrutinize novel phylogenetic positions. With the identification of the antifungal antibiotic solanimycin in a broad diversity of phytopathogenic Dickeya spp., we provide further support for the potential of plant-associated bacteria for the biosynthesis of novel antimicrobials. The complex regulatory networks involved in solanimycin production reflect the high metabolic cost of bacterial secondary metabolism. This metabolic regulatory control makes many antibiotics cryptic under standard laboratory conditions, and mimicking environmental conditions, as shown here, is a strategy to activate cryptic antibiotic clusters.
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Murata K, Suenaga M, Kai K. Genome Mining Discovery of Protegenins A-D, Bacterial Polyynes Involved in the Antioomycete and Biocontrol Activities of Pseudomonas protegens. ACS Chem Biol 2022; 17:3313-3320. [PMID: 34015911 DOI: 10.1021/acschembio.1c00276] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Some bacteria uniquely produce "bacterial polyynes", which possess a conjugated C≡C bond starting with a terminal alkyne, and use them as chemical weapons against hosts and competitors. Pseudomonas protegens Cab57, a biocontrol agent against plant pathogens, has an orphan biosynthetic gene cluster for bacterial polyynes (named protegenins). In this study, the isolation, structure elucidation, and biological characterization of protegenins A-D are reported. The structures of protegenins A-D determined by spectroscopic and chemical techniques were octadecanoic acid derivatives possessing an ene-tetrayne, ene-triyne-ene, or ene-triyne moiety. The protegenins exhibited weak to strong antioomycete activity against Pythium ultimum OPU774. The deletion of proA, a protegenin biosynthetic gene, resulted in the reduction of the antioomycete activity of P. protegens. The Gac/Rsm system, a quorum sensing-like system of Pseudomonas bacteria, regulated the production of protegenins. The production profile of protegenins was dependent on the culturing conditions, suggesting a control mechanism for protegenin production selectivity. P. protegens suppressed the damping-off of cucumber seedlings caused by P. ultimum, and this protective effect was reduced in the proA-deletion mutant. Altogether, protegenins are a new class of bacterial polyynes which contribute to the antioomycete and plant-protective effects of P. protegens.
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Affiliation(s)
- Kazuya Murata
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Mayuna Suenaga
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Kenji Kai
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
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18
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Cuervo L, Méndez C, Salas JA, Olano C, Malmierca MG. Volatile Compounds in Actinomycete Communities: A New Tool for Biosynthetic Gene Cluster Activation, Cooperative Growth Promotion, and Drug Discovery. Cells 2022; 11:3510. [PMID: 36359906 PMCID: PMC9655753 DOI: 10.3390/cells11213510] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 10/30/2022] [Accepted: 11/01/2022] [Indexed: 07/30/2023] Open
Abstract
The increasing appearance of multiresistant pathogens, as well as emerging diseases, has highlighted the need for new strategies to discover natural compounds that can be used as therapeutic alternatives, especially in the genus Streptomyces, which is one of the largest producers of bioactive metabolites. In recent years, the study of volatile compounds (VOCs) has raised interest because of the variety of their biological properties in addition to their involvement in cell communication. In this work, we analyze the implications of VOCs as mediating molecules capable of inducing the activation of biosynthetic pathways of bioactive compounds in surrounding Actinomycetes. For this purpose, several strains of Streptomyces were co-cultured in chamber devices that allowed VOC exchange while avoiding physical contact. In several of those strains, secondary metabolism was activated by VOCs emitted by companion strains, resulting in increased antibiotic production and synthesis of new VOCs. This study shows a novel strategy to exploit the metabolic potential of Actinomycetes as well as emphasizes the importance of studying the interactions between different microorganisms sharing the same ecological niche.
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Affiliation(s)
- Lorena Cuervo
- Functional Biology Department, University of Oviedo, 33006 Oviedo, Spain
- University Institute of Oncology of Asturias (I.U.O.P.A), University of Oviedo, 33006 Oviedo, Spain
- Health Research Institute of Asturias (ISPA), 33011 Oviedo, Spain
| | - Carmen Méndez
- Functional Biology Department, University of Oviedo, 33006 Oviedo, Spain
- University Institute of Oncology of Asturias (I.U.O.P.A), University of Oviedo, 33006 Oviedo, Spain
- Health Research Institute of Asturias (ISPA), 33011 Oviedo, Spain
| | - José A. Salas
- Functional Biology Department, University of Oviedo, 33006 Oviedo, Spain
- University Institute of Oncology of Asturias (I.U.O.P.A), University of Oviedo, 33006 Oviedo, Spain
- Health Research Institute of Asturias (ISPA), 33011 Oviedo, Spain
| | - Carlos Olano
- Functional Biology Department, University of Oviedo, 33006 Oviedo, Spain
- University Institute of Oncology of Asturias (I.U.O.P.A), University of Oviedo, 33006 Oviedo, Spain
- Health Research Institute of Asturias (ISPA), 33011 Oviedo, Spain
| | - Mónica G. Malmierca
- Functional Biology Department, University of Oviedo, 33006 Oviedo, Spain
- University Institute of Oncology of Asturias (I.U.O.P.A), University of Oviedo, 33006 Oviedo, Spain
- Health Research Institute of Asturias (ISPA), 33011 Oviedo, Spain
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Interkingdom assemblages in human saliva display group-level surface mobility and disease-promoting emergent functions. Proc Natl Acad Sci U S A 2022; 119:e2209699119. [PMID: 36191236 PMCID: PMC9565521 DOI: 10.1073/pnas.2209699119] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Fungi and bacteria form multicellular biofilms causing many human infections. How such distinctive microbes act in concert spatiotemporally to coordinate disease-promoting functionality remains understudied. Using multiscale real-time microscopy and computational analysis, we investigate the dynamics of fungal and bacterial interactions in human saliva and their biofilm development on tooth surfaces. We discovered structured interkingdom assemblages displaying emergent functionalities to enhance collective surface colonization, survival, and growth. Further analyses revealed an unexpected group-level surface mobility with coordinated “leaping-like” and “walking-like” motions while continuously growing. These mobile groups of growing cells promote rapid spatial spreading of both species across surfaces, causing more extensive tooth decay. Our findings show multicellular interkingdom assemblages acting like supraorganisms with functionalities that cannot be achieved without coassembly. Fungi and bacteria often engage in complex interactions, such as the formation of multicellular biofilms within the human body. Knowledge about how interkingdom biofilms initiate and coalesce into higher-level communities and which functions the different species carry out during biofilm formation remain limited. We found native-state assemblages of Candida albicans (fungi) and Streptococcus mutans (bacteria) with highly structured arrangement in saliva from diseased patients with childhood tooth decay. Further analyses revealed that bacterial clusters are attached within a network of fungal yeasts, hyphae, and exopolysaccharides, which bind to surfaces as a preassembled cell group. The interkingdom assemblages exhibit emergent functions, including enhanced surface colonization and growth rate, stronger tolerance to antimicrobials, and improved shear resistance, compared to either species alone. Notably, we discovered that the interkingdom assemblages display a unique form of migratory spatial mobility that enables fast spreading of biofilms across surfaces and causes enhanced, more extensive tooth decay. Using mutants, selective inactivation of species, and selective matrix removal, we demonstrate that the enhanced stress resistance and surface mobility arise from the exopolymeric matrix and require the presence of both species in the assemblage. The mobility is directed by fungal filamentation as hyphae extend and contact the surface, lifting the assemblage with a “forward-leaping motion.” Bacterial cell clusters can “hitchhike” on this mobile unit while continuously growing, to spread across the surface three-dimensionally and merge with other assemblages, promoting community expansion. Together, our results reveal an interkingdom assemblage in human saliva that behaves like a supraorganism, with disease-causing emergent functionalities that cannot be achieved without coassembly.
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Niehs SP, Scherlach K, Dose B, Uzum Z, Stinear TP, Pidot SJ, Hertweck C. A highly conserved gene locus in endofungal bacteria codes for the biosynthesis of symbiosis-specific cyclopeptides. PNAS NEXUS 2022; 1:pgac152. [PMID: 36714835 PMCID: PMC9802438 DOI: 10.1093/pnasnexus/pgac152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 06/30/2022] [Accepted: 08/03/2022] [Indexed: 02/01/2023]
Abstract
The tight association of the pathogenic fungus Rhizopus microsporus and its toxin-producing, bacterial endosymbionts (Mycetohabitans spp.) is distributed worldwide and has significance for agriculture, food production, and human health. Intriguingly, the endofungal bacteria are essential for the propagation of the fungal host. Yet, little is known about chemical mediators fostering the symbiosis, and universal metabolites that support the mutualistic relationship have remained elusive. Here, we describe the discovery of a complex of specialized metabolites produced by endofungal bacteria under symbiotic conditions. Through full genome sequencing and comparative genomics of eight endofungal symbiont strains from geographically distant regions, we discovered a conserved gene locus (hab) for a nonribosomal peptide synthetase as a unifying trait. Bioinformatics analyses, targeted gene deletions, and chemical profiling uncovered unprecedented depsipeptides (habitasporins) whose structures were fully elucidated. Computational network analysis and labeling experiments granted insight into the biosynthesis of their nonproteinogenic building blocks (pipecolic acid and β-phenylalanine). Deletion of the hab gene locus was shown to impair the ability of the bacteria to enter their fungal host. Our study unveils a common principle of the endosymbiotic lifestyle of Mycetohabitans species and expands the repertoire of characterized chemical mediators of a globally occurring mutualistic association.
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Affiliation(s)
| | | | - Benjamin Dose
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (Leibniz-HKI), Beutenbergstr. 11a, 07745 Jena, Germany
| | - Zerrin Uzum
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (Leibniz-HKI), Beutenbergstr. 11a, 07745 Jena, Germany
| | - Timothy P Stinear
- Department of Microbiology and Immunology, Doherty Institute, University of Melbourne, 792 Elizabeth Street, Melbourne, 3000, Australia
| | - Sacha J Pidot
- Department of Microbiology and Immunology, Doherty Institute, University of Melbourne, 792 Elizabeth Street, Melbourne, 3000, Australia
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Zhang W, Luo X, Mei YZ, Yang Q, Zhang AY, Chen M, Mei Y, Ma CY, Du YC, Li M, Zhu Q, Sun K, Xu FJ, Dai CC. Priming of rhizobial nodulation signaling in the mycosphere accelerates nodulation of legume hosts. THE NEW PHYTOLOGIST 2022; 235:1212-1230. [PMID: 35488499 DOI: 10.1111/nph.18192] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 04/20/2022] [Indexed: 06/14/2023]
Abstract
The simultaneous symbiosis of leguminous plants with two root mutualists, endophytic fungi and rhizobia is common in nature, yet how two mutualists interact and co-exist before infecting plants and the concomitant effects on nodulation are less understood. Using a combination of metabolic analysis, fungal deletion mutants and comparative transcriptomics, we demonstrated that Bradyrhizobium and a facultatively biotrophic fungus, Phomopsis liquidambaris, interacted to stimulate fungal flavonoid production, and thereby primed Bradyrhizobial nodulation signaling, enhancing Bradyrhizobial responses to root exudates and leading to early nodulation of peanut (Arachis hypogaea), and such effects were compromised when disturbing fungal flavonoid biosynthesis. Stress sensitivity assays and reactive oxygen species (ROS) determination revealed that flavonoid production acted as a strategy to alleviate hyphal oxidative stress during P. liquidambaris-Bradyrhizobial interactions. By investigating the interactions between P. liquidambaris and a collection of 38 rhizobacteria, from distinct bacterial genera, we additionally showed that the flavonoid-ROS module contributed to the maintenance of fungal and bacterial co-existence, and fungal niche colonization under soil conditions. Our results demonstrate for the first time that rhizobial nodulation signaling can be primed by fungi before symbiosis with host plants and highlight the importance of flavonoid in tripartite interactions between legumes, beneficial fungi and rhizobia.
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Affiliation(s)
- Wei Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Xue Luo
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Yan-Zhen Mei
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Qian Yang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Ai-Yue Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Man Chen
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Yan Mei
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Chen-Yu Ma
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Ying-Chun Du
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Min Li
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Qiang Zhu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Kai Sun
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
| | - Fang-Ji Xu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
- Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences (SAAS), Jinan, 250100, Shandong, China
| | - Chuan-Chao Dai
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
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22
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Lee SR, Seyedsayamdost MR. Induction of Diverse Cryptic Fungal Metabolites by Steroids and Channel Blockers. Angew Chem Int Ed Engl 2022; 61:e202204519. [PMID: 35509119 PMCID: PMC9276648 DOI: 10.1002/anie.202204519] [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: 03/28/2022] [Indexed: 07/20/2023]
Abstract
Fungi offer a deep source of natural products but remain underutilized. Most biosynthetic gene clusters (BGCs) that can be detected are silent or "cryptic" in standard lab cultures and their products are thus not interrogated in routine screens. As genetic alterations are difficult and some strains can only be grown on agar, we have herein applied an agar-based high-throughput chemical genetic screen to identify inducers of fungal BGCs. Using R. solani and S. sclerotiorum as test cases, we report 13 cryptic metabolites in four compound groups, including sclerocyclane, a natural product with a novel scaffold. Steroids were the best elicitors and follow-up studies showed that plant-steroids trigger sclerocyclane synthesis, which shows antibiotic activity against B. plantarii, an ecological competitor of S. sclerotiorum. Our results open new paths to exploring the chemical ecology of fungal-plant interactions and provide a genetics-free approach for uncovering cryptic fungal metabolites.
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Affiliation(s)
- Seoung Rak Lee
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Mohammad R Seyedsayamdost
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
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23
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Hagh-Doust N, Färkkilä SM, Hosseyni Moghaddam MS, Tedersoo L. Symbiotic fungi as biotechnological tools: Methodological challenges and relative benefits in agriculture and forestry. FUNGAL BIOL REV 2022. [DOI: 10.1016/j.fbr.2022.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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24
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Lee SR, Seyedsayamdost MR. Induction of Diverse Cryptic Fungal Metabolites by Steroids and Channel Blockers. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202204519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Seoung Rak Lee
- Department of Chemistry Princeton University Princeton NJ 08544 USA
| | - Mohammad R. Seyedsayamdost
- Department of Chemistry Princeton University Princeton NJ 08544 USA
- Department of Molecular Biology Princeton University Princeton NJ 08544 USA
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25
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Mungan MD, Harbig TA, Perez NH, Edenhart S, Stegmann E, Nieselt K, Ziemert N. Secondary Metabolite Transcriptomic Pipeline (SeMa-Trap), an expression-based exploration tool for increased secondary metabolite production in bacteria. Nucleic Acids Res 2022; 50:W682-W689. [PMID: 35580059 PMCID: PMC9252823 DOI: 10.1093/nar/gkac371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 04/20/2022] [Accepted: 04/29/2022] [Indexed: 11/14/2022] Open
Abstract
For decades, natural products have been used as a primary resource in drug discovery pipelines to find new antibiotics, which are mainly produced as secondary metabolites by bacteria. The biosynthesis of these compounds is encoded in co-localized genes termed biosynthetic gene clusters (BGCs). However, BGCs are often not expressed under laboratory conditions. Several genetic manipulation strategies have been developed in order to activate or overexpress silent BGCs. Significant increases in production levels of secondary metabolites were indeed achieved by modifying the expression of genes encoding regulators and transporters, as well as genes involved in resistance or precursor biosynthesis. However, the abundance of genes encoding such functions within bacterial genomes requires prioritization of the most promising ones for genetic manipulation strategies. Here, we introduce the ‘Secondary Metabolite Transcriptomic Pipeline’ (SeMa-Trap), a user-friendly web-server, available at https://sema-trap.ziemertlab.com. SeMa-Trap facilitates RNA-Seq based transcriptome analyses, finds co-expression patterns between certain genes and BGCs of interest, and helps optimize the design of comparative transcriptomic analyses. Finally, SeMa-Trap provides interactive result pages for each BGC, allowing the easy exploration and comparison of expression patterns. In summary, SeMa-Trap allows a straightforward prioritization of genes that could be targeted via genetic engineering approaches to (over)express BGCs of interest.
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Affiliation(s)
- Mehmet Direnç Mungan
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany.,Interfaculty Institute for Bioinformatics and Medical Informatics (IBMI), University of Tübingen, 72076 Tübingen, Germany.,German Center for Infection Research (DZIF), Partnersite Tübingen, 72076 Tübingen, Germany
| | - Theresa Anisja Harbig
- Interfaculty Institute for Bioinformatics and Medical Informatics (IBMI), University of Tübingen, 72076 Tübingen, Germany
| | - Naybel Hernandez Perez
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
| | - Simone Edenhart
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
| | - Evi Stegmann
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany.,German Center for Infection Research (DZIF), Partnersite Tübingen, 72076 Tübingen, Germany
| | - Kay Nieselt
- Interfaculty Institute for Bioinformatics and Medical Informatics (IBMI), University of Tübingen, 72076 Tübingen, Germany
| | - Nadine Ziemert
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany.,Interfaculty Institute for Bioinformatics and Medical Informatics (IBMI), University of Tübingen, 72076 Tübingen, Germany.,German Center for Infection Research (DZIF), Partnersite Tübingen, 72076 Tübingen, Germany
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26
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Schmidt S, Kildgaard S, Guo H, Beemelmanns C, Poulsen M. The chemical ecology of the fungus-farming termite symbiosis. Nat Prod Rep 2022; 39:231-248. [PMID: 34879123 PMCID: PMC8865390 DOI: 10.1039/d1np00022e] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Indexed: 01/19/2023]
Abstract
Covering: September 1972 to December 2020Explorations of complex symbioses have often elucidated a plethora of previously undescribed chemical compounds that may serve ecological functions in signalling, communication or defence. A case in point is the subfamily of termites that cultivate a fungus as their primary food source and maintain complex bacterial communities, from which a series of novel compound discoveries have been made. Here, we summarise the origins and types of 375 compounds that have been discovered from the symbiosis over the past four decades and discuss the potential for synergistic actions between compounds within the complex chemical mixtures in which they exist. We go on to highlight how vastly underexplored the diversity and geographic distribution of the symbiosis is, which leaves ample potential for natural product discovery of compounds of both ecological and medical importance.
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Affiliation(s)
- Suzanne Schmidt
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark.
| | - Sara Kildgaard
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark.
| | - Huijuan Guo
- Leibniz Institute for Natural Product Research and Infection Biology e.V., Hans-Knöll-Institute (HKI), Beutenbergstraße 11a, 07745 Jena, Germany
| | - Christine Beemelmanns
- Leibniz Institute for Natural Product Research and Infection Biology e.V., Hans-Knöll-Institute (HKI), Beutenbergstraße 11a, 07745 Jena, Germany
| | - Michael Poulsen
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark.
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27
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Enhanced Virulence of Candida albicans by Staphylococcus aureus: Evidence in Clinical Bloodstream Infections and Infected Zebrafish Embryos. J Fungi (Basel) 2021; 7:jof7121099. [PMID: 34947081 PMCID: PMC8706905 DOI: 10.3390/jof7121099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 12/10/2021] [Accepted: 12/16/2021] [Indexed: 11/16/2022] Open
Abstract
Coinfection with Candida and Staphylococcus results in higher mortality in animal studies. However, the pathogenesis and interplay between C. albicans and S. aureus in bloodstream infections (BSIs) is unclear. This study determines the clinical features and outcomes of mixed C. albicans/S. aureus (CA/SA) BSIs and biofilm formation on pathogenesis during coinfection. Demographics and outcomes for mixed BSIs and monomicrobial candidemia were compared. Compared to 115 monomicrobial C. albicans BSIs, 22 patients with mixed CA/SA BSIs exhibited a significantly higher mortality rate and shorter survival time. In vitro and in vivo biofilm analysis showed that C. albicans accounted for the main biofilm architecture, and S. aureus increased its amount. Antibiotic tolerance in S. aureus, which adhered to Candida hyphae observed by scanning electron microscope, was demonstrated by the presence of wild-type C. albicans co-biofilm. Upregulation in exotoxin genes of S. aureus was evidenced by quantitative RT-PCR when a co-biofilm was formed with C. albicans. Mixed CA/SA BSIs result in a higher mortality rate in patients and in vivo surrogate models experiments. This study demonstrates that the virulence enhancement of C. albicans and S. aureus during co-biofilm formation contributes to the high mortality rate.
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28
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Mungan MD, Blin K, Ziemert N. ARTS-DB: a database for antibiotic resistant targets. Nucleic Acids Res 2021; 50:D736-D740. [PMID: 34718689 PMCID: PMC8728217 DOI: 10.1093/nar/gkab940] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 09/14/2021] [Accepted: 10/01/2021] [Indexed: 12/13/2022] Open
Abstract
As a result of the continuous evolution of drug resistant bacteria, new antibiotics are urgently needed. Encoded by biosynthetic gene clusters (BGCs), antibiotic compounds are mostly produced by bacteria. With the exponential increase in the number of publicly available, sequenced genomes and the advancements of BGC prediction tools, genome mining algorithms have uncovered millions of uncharacterized BGCs for further evaluation. Since compound identification and characterization remain bottlenecks, a major challenge is prioritizing promising BGCs. Recently, researchers adopted self-resistance based strategies allowing them to predict the biological activities of natural products encoded by uncharacterized BGCs. Since 2017, the Antibiotic Resistant Target Seeker (ARTS) facilitated this so-called target-directed genome mining (TDGM) approach for the prioritization of BGCs encoding potentially novel antibiotics. Here, we present the ARTS database, available at https://arts-db.ziemertlab.com/. The ARTS database provides pre-computed ARTS results for >70,000 genomes and metagenome assembled genomes in total. Advanced search queries allow users to rapidly explore the fundamental criteria of TDGM such as BGC proximity, duplication and horizontal gene transfers of essential housekeeping genes. Furthermore, the ARTS database provides results interconnected throughout the bacterial kingdom as well as links to known databases in natural product research.
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Affiliation(s)
- Mehmet Direnç Mungan
- Interfaculty Institute of Microbiology and Infection Medicine, Institute for Bioinformatics and Medical Informatics, University of Tübingen, 72076 Tübingen, Germany.,German Center for Infection Research (DZIF), Partner Site Tübingen, 72076 Tübingen, Germany
| | - Kai Blin
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet Bygning 220, 2800 Kgs. Lyngby, Denmark
| | - Nadine Ziemert
- Interfaculty Institute of Microbiology and Infection Medicine, Institute for Bioinformatics and Medical Informatics, University of Tübingen, 72076 Tübingen, Germany.,German Center for Infection Research (DZIF), Partner Site Tübingen, 72076 Tübingen, Germany
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29
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Dose B, Thongkongkaew T, Zopf D, Kim HJ, Bratovanov EV, García‐Altares M, Scherlach K, Kumpfmüller J, Ross C, Hermenau R, Niehs S, Silge A, Hniopek J, Schmitt M, Popp J, Hertweck C. Multimodal Molecular Imaging and Identification of Bacterial Toxins Causing Mushroom Soft Rot and Cavity Disease. Chembiochem 2021; 22:2901-2907. [PMID: 34232540 PMCID: PMC8518961 DOI: 10.1002/cbic.202100330] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Indexed: 12/29/2022]
Abstract
Soft rot disease of edible mushrooms leads to rapid degeneration of fungal tissue and thus severely affects farming productivity worldwide. The bacterial mushroom pathogen Burkholderia gladioli pv. agaricicola has been identified as the cause. Yet, little is known about the molecular basis of the infection, the spatial distribution and the biological role of antifungal agents and toxins involved in this infectious disease. We combine genome mining, metabolic profiling, MALDI-Imaging and UV Raman spectroscopy, to detect, identify and visualize a complex of chemical mediators and toxins produced by the pathogen during the infection process, including toxoflavin, caryoynencin, and sinapigladioside. Furthermore, targeted gene knockouts and in vitro assays link antifungal agents to prevalent symptoms of soft rot, mushroom browning, and impaired mycelium growth. Comparisons of related pathogenic, mutualistic and environmental Burkholderia spp. indicate that the arsenal of antifungal agents may have paved the way for ancestral bacteria to colonize niches where frequent, antagonistic interactions with fungi occur. Our findings not only demonstrate the power of label-free, in vivo detection of polyyne virulence factors by Raman imaging, but may also inspire new approaches to disease control.
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Affiliation(s)
- Benjamin Dose
- Leibniz Institute for Natural Product Research and Infection BiologyHKIBeutenbergstr. 11a07745JenaGermany
| | - Tawatchai Thongkongkaew
- Leibniz Institute for Natural Product Research and Infection BiologyHKIBeutenbergstr. 11a07745JenaGermany
| | - David Zopf
- Institute of Physical Chemistry (IPC) and Abbe Center of PhotonicsHelmholtzweg 407743JenaGermany
- Leibniz Institute of Photonic Technology (IPHT) JenaMember of the Leibniz Research Alliance – Leibniz Health TechnologiesAlbert-Einstein-Straße 907745JenaGermany
| | - Hak Joong Kim
- Leibniz Institute for Natural Product Research and Infection BiologyHKIBeutenbergstr. 11a07745JenaGermany
| | - Evgeni V. Bratovanov
- Leibniz Institute for Natural Product Research and Infection BiologyHKIBeutenbergstr. 11a07745JenaGermany
| | - María García‐Altares
- Leibniz Institute for Natural Product Research and Infection BiologyHKIBeutenbergstr. 11a07745JenaGermany
| | - Kirstin Scherlach
- Leibniz Institute for Natural Product Research and Infection BiologyHKIBeutenbergstr. 11a07745JenaGermany
| | - Jana Kumpfmüller
- Leibniz Institute for Natural Product Research and Infection BiologyHKIBeutenbergstr. 11a07745JenaGermany
| | - Claudia Ross
- Leibniz Institute for Natural Product Research and Infection BiologyHKIBeutenbergstr. 11a07745JenaGermany
| | - Ron Hermenau
- Leibniz Institute for Natural Product Research and Infection BiologyHKIBeutenbergstr. 11a07745JenaGermany
| | - Sarah Niehs
- Leibniz Institute for Natural Product Research and Infection BiologyHKIBeutenbergstr. 11a07745JenaGermany
| | - Anja Silge
- Institute of Physical Chemistry (IPC) and Abbe Center of PhotonicsHelmholtzweg 407743JenaGermany
| | - Julian Hniopek
- Institute of Physical Chemistry (IPC) and Abbe Center of PhotonicsHelmholtzweg 407743JenaGermany
- Leibniz Institute of Photonic Technology (IPHT) JenaMember of the Leibniz Research Alliance – Leibniz Health TechnologiesAlbert-Einstein-Straße 907745JenaGermany
| | - Michael Schmitt
- Institute of Physical Chemistry (IPC) and Abbe Center of PhotonicsHelmholtzweg 407743JenaGermany
| | - Jürgen Popp
- Institute of Physical Chemistry (IPC) and Abbe Center of PhotonicsHelmholtzweg 407743JenaGermany
- Leibniz Institute of Photonic Technology (IPHT) JenaMember of the Leibniz Research Alliance – Leibniz Health TechnologiesAlbert-Einstein-Straße 907745JenaGermany
| | - Christian Hertweck
- Leibniz Institute for Natural Product Research and Infection BiologyHKIBeutenbergstr. 11a07745JenaGermany
- Faculty of Biological SciencesFriedrich Schiller University Jena07743JenaGermany
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30
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Rämä T, Quandt CA. Improving Fungal Cultivability for Natural Products Discovery. Front Microbiol 2021; 12:706044. [PMID: 34603232 PMCID: PMC8481835 DOI: 10.3389/fmicb.2021.706044] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 08/23/2021] [Indexed: 11/13/2022] Open
Abstract
The pool of fungal secondary metabolites can be extended by activating silent gene clusters of cultured strains or by using sensitive biological assays that detect metabolites missed by analytical methods. Alternatively, or in parallel with the first approach, one can increase the diversity of existing culture collections to improve the access to new natural products. This review focuses on the latter approach of screening previously uncultured fungi for chemodiversity. Both strategies have been practiced since the early days of fungal biodiscovery, yet relatively little has been done to overcome the challenge of cultivability of as-yet-uncultivated fungi. Whereas earlier cultivability studies using media formulations and biological assays to scrutinize fungal growth and associated factors were actively conducted, the application of modern omics methods remains limited to test how to culture the fungal dark matter and recalcitrant groups of described fungi. This review discusses the development of techniques to increase the cultivability of filamentous fungi that include culture media formulations and the utilization of known chemical growth factors, in situ culturing and current synthetic biology approaches that build upon knowledge from sequenced genomes. We list more than 100 growth factors, i.e., molecules, biological or physical factors that have been demonstrated to induce spore germination as well as tens of inducers of mycelial growth. We review culturing conditions that can be successfully manipulated for growth of fungi and visit recent information from omics methods to discuss the metabolic basis of cultivability. Earlier work has demonstrated the power of co-culturing fungi with their host, other microorganisms or their exudates to increase their cultivability. Co-culturing of two or more organisms is also a strategy used today for increasing cultivability. However, fungi possess an increased risk for cross-contaminations between isolates in existing in situ or microfluidics culturing devices. Technological improvements for culturing fungi are discussed in the review. We emphasize that improving the cultivability of fungi remains a relevant strategy in drug discovery and underline the importance of ecological and taxonomic knowledge in culture-dependent drug discovery. Combining traditional and omics techniques such as single cell or metagenome sequencing opens up a new era in the study of growth factors of hundreds of thousands of fungal species with high drug discovery potential.
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Affiliation(s)
- Teppo Rämä
- Marbio, Norwegian College of Fishery Science, University of Tromsø – The Arctic University of Norway, Tromsø, Norway
| | - C. Alisha Quandt
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Boulder, CO, United States
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31
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Bach E, Passaglia LMP, Jiao J, Gross H. Burkholderia in the genomic era: from taxonomy to the discovery of new antimicrobial secondary metabolites. Crit Rev Microbiol 2021; 48:121-160. [PMID: 34346791 DOI: 10.1080/1040841x.2021.1946009] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Species of Burkholderia are highly versatile being found not only abundantly in soil, but also as plants and animals' commensals or pathogens. Their complex multireplicon genomes harbour an impressive number of polyketide synthase (PKS) and nonribosomal peptide-synthetase (NRPS) genes coding for the production of antimicrobial secondary metabolites (SMs), which have been successfully deciphered by genome-guided tools. Moreover, genome metrics supported the split of this genus into Burkholderia sensu stricto (s.s.) and five new other genera. Here, we show that the successful antimicrobial SMs producers belong to Burkholderia s.s. Additionally, we reviewed the occurrence, bioactivities, modes of action, structural, and biosynthetic information of thirty-eight Burkholderia antimicrobial SMs shedding light on their diversity, complexity, and uniqueness as well as the importance of genome-guided strategies to facilitate their discovery. Several Burkholderia NRPS and PKS display unusual features, which are reflected in their structural diversity, important bioactivities, and varied modes of action. Up to now, it is possible to observe a general tendency of Burkholderia SMs being more active against fungi. Although the modes of action and biosynthetic gene clusters of many SMs remain unknown, we highlight the potential of Burkholderia SMs as alternatives to fight against new diseases and antibiotic resistance.
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Affiliation(s)
- Evelise Bach
- Departamento de Genética and Programa de Pós-graduação em Genética e Biologia Molecular, Instituto de Biociências, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Luciane Maria Pereira Passaglia
- Departamento de Genética and Programa de Pós-graduação em Genética e Biologia Molecular, Instituto de Biociências, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Junjing Jiao
- Department for Pharmaceutical Biology, Pharmaceutical Institute, University of Tübingen, Tübingen, Germany
| | - Harald Gross
- Department for Pharmaceutical Biology, Pharmaceutical Institute, University of Tübingen, Tübingen, Germany
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32
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Matilla MA. Facing crises in the 21st century: microfluidics approaches for antibiotic discovery. Microb Biotechnol 2021; 15:392-394. [PMID: 34333833 PMCID: PMC8867967 DOI: 10.1111/1751-7915.13908] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 11/28/2022] Open
Abstract
We urgently need new antibiotics to counteract the rising in the emergence of multidrug‐resistant microorganisms. To improve the identification of antimicrobial compounds of microbial origin, numerous multidisciplinary approaches are being implemented. However, the development of innovative microbial cultivation strategies is necessary to exploit the full biosynthetic potential of non‐culturable microorganisms. Here, I highlight various articles that employ high‐throughput microfluidic‐based strategies to identify novel antimicrobial metabolites based on bacterial activities. The rapid development of this technology will likely advance the field of antibiotic discovery.
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Affiliation(s)
- Miguel A Matilla
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, Granada, 18008, Spain
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33
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Scherlach K, Hertweck C. Mining and unearthing hidden biosynthetic potential. Nat Commun 2021; 12:3864. [PMID: 34162873 PMCID: PMC8222398 DOI: 10.1038/s41467-021-24133-5] [Citation(s) in RCA: 107] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 06/04/2021] [Indexed: 12/11/2022] Open
Abstract
Genetically encoded small molecules (secondary metabolites) play eminent roles in ecological interactions, as pathogenicity factors and as drug leads. Yet, these chemical mediators often evade detection, and the discovery of novel entities is hampered by low production and high rediscovery rates. These limitations may be addressed by genome mining for biosynthetic gene clusters, thereby unveiling cryptic metabolic potential. The development of sophisticated data mining methods and genetic and analytical tools has enabled the discovery of an impressive array of previously overlooked natural products. This review shows the newest developments in the field, highlighting compound discovery from unconventional sources and microbiomes. Natural products are an important source of bioactive compounds and have versatile applications in different fields, but their discovery is challenging. Here, the authors review the recent developments in genome mining for discovery of natural products, focusing on compounds from unconventional microorganisms and microbiomes.
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Affiliation(s)
- Kirstin Scherlach
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, HKI, Jena, Germany
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, HKI, Jena, Germany. .,Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany.
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34
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Herkersdorf S, Krüger T, Wein P, Löffler S, Fontaine T, Gressler M, Hertweck C, Brakhage AA, Hoffmeister D. Bacterial cell wall-degrading enzymes induce basidiomycete natural product biosynthesis. Environ Microbiol 2021; 23:4360-4371. [PMID: 34081381 DOI: 10.1111/1462-2920.15621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 05/26/2021] [Accepted: 05/31/2021] [Indexed: 12/12/2022]
Abstract
Natural products play a vital role for intermicrobial interactions. In the basidiomycete arena an important representative is variegatic acid, a lactone natural product pigment whose ecological relevance stems from both inhibiting bacterial swarming and from indirect participation in breakdown of organic matter by brown-rotting fungi. Previous work showed that the presence of bacteria stimulates variegatic acid production. However, the actual external molecular trigger that prompts its biosynthesis in the mushroom hyphae remained unknown. Here, we report on the identification of Bacillus subtilis subtilisin E (AprE) and chitosanase (Csn) as primary inducers of pulvinic acid pigment formation. Using the established co-culture system of B. subtilis and Serpula lacrymans, we used activity-guided FPLC-based fractionation of B. subtilis culture supernatants and subsequent peptide fingerprinting to identify candidates, and their role was corroborated by means of a pigment production assay using heterologously produced chitosanase and subtilisin. B. subtilis mutants defective in either the aprE or the csn gene still triggered pigmentation, yet to a lower degree, which points to a multicausal scenario and suggests the combined activity of these cell wall polymer-attacking enzymes as true stimulus.
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Affiliation(s)
- Sebastian Herkersdorf
- Department of Pharmaceutical Microbiology at the Leibniz Institute for Natural Product Research and Infection Biology, Friedrich Schiller University, Beutenbergstrasse 11a, Jena, 07745, Germany
| | - Thomas Krüger
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
| | - Philipp Wein
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
| | - Susanne Löffler
- Department of Pharmaceutical Microbiology at the Leibniz Institute for Natural Product Research and Infection Biology, Friedrich Schiller University, Beutenbergstrasse 11a, Jena, 07745, Germany
| | - Thierry Fontaine
- Department of Mycology, Fungal Biology and Pathogenicity, Institut Pasteur, Paris, France
| | - Markus Gressler
- Department of Pharmaceutical Microbiology at the Leibniz Institute for Natural Product Research and Infection Biology, Friedrich Schiller University, Beutenbergstrasse 11a, Jena, 07745, Germany
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany.,Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany.,Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany
| | - Dirk Hoffmeister
- Department of Pharmaceutical Microbiology at the Leibniz Institute for Natural Product Research and Infection Biology, Friedrich Schiller University, Beutenbergstrasse 11a, Jena, 07745, Germany
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Vij R, Hube B, Brunke S. Uncharted territories in the discovery of antifungal and antivirulence natural products from bacteria. Comput Struct Biotechnol J 2021; 19:1244-1252. [PMID: 33680363 PMCID: PMC7905183 DOI: 10.1016/j.csbj.2021.02.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 02/02/2021] [Accepted: 02/02/2021] [Indexed: 12/26/2022] Open
Abstract
Many fungi can cause deadly diseases in humans, and nearly every human will suffer from some kind of fungal infection in their lives. Only few antifungals are available, and some of these fail to treat intrinsically resistant species and the ever-increasing number of fungal strains that have acquired resistance. In nature, bacteria and fungi display versatile interactions that range from friendly co-existence to predation. The first antifungal drugs, nystatin and amphotericin B, were discovered in bacteria as mediators of such interactions, and bacteria continue to be an important source of antifungals. To learn more about the ecological bacterial-fungal interactions that drive the evolution of natural products and exploit them, we need to identify environments where such interactions are pronounced, and diverse. Here, we systematically analyze historic and recent developments in this field to identify potentially under-investigated niches and resources. We also discuss alternative strategies to treat fungal infections by utilizing the antagonistic potential of bacteria to target fungal stress pathways and virulence factors, and thereby suppress the evolution of antifungal resistance.
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Affiliation(s)
- Raghav Vij
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute Jena (HKI), Germany
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute Jena (HKI), Germany
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Sascha Brunke
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute Jena (HKI), Germany
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Heydari S, Siavoshi F, Sarrafnejad A, Malekzadeh R. Coniochaeta fungus benefits from its intracellular bacteria to form biofilm and defend against other fungi. Arch Microbiol 2021; 203:1357-1366. [PMID: 33386870 DOI: 10.1007/s00203-020-02122-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/10/2020] [Accepted: 11/18/2020] [Indexed: 11/30/2022]
Abstract
During cultivation of a gastric fungus, Coniochaeta polymorpha, growth of Nocardia colonies on top of the fungal culture raised the question whether bacteria originated from inside of fungus. In this study, the likelihood of intracellular origin of bacteria as well as interaction of two microorganisms was assessed. Fluorescence and electron microscopy showed occurrence of several bacterial cells in fungal cytoplasm. A thick biofilm was observed on the surface of co-culture compared with thin one on bacterial and none on fungal monocultures. Field emission scanning electron microscopy (FESEM) micrographs of co-culture showed a dense network of fungal and bacterial cells embedded in a slime-like layer. Dual cultures revealed antagonistic activity of both fungus and bacteria against three Candida species. These findings indicate that Nocardia isolate identified in this study originated from the inside of fungus C. polymorpha. Intracellular bacteria could benefit the fungal host by producing a rigid biofilm and an antifungal compound.
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Affiliation(s)
- Samira Heydari
- Department of Microbiology, School of Biology, University College of Sciences, University of Tehran, Tehran, Iran
| | - Farideh Siavoshi
- Department of Microbiology, School of Biology, University College of Sciences, University of Tehran, Tehran, Iran.
| | - Abdolfattah Sarrafnejad
- Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Reza Malekzadeh
- Digestive Disease Research Institute, Tehran University of Medical Sciences, Tehran, Iran
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