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Lee SR, Dayras M, Fricke J, Guo H, Balluff S, Schalk F, Yu JS, Jeong SY, Morgenstern B, Slippers B, Beemelmanns C, Kim KH. Molecular networking and computational NMR analyses uncover six polyketide-terpene hybrids from termite-associated Xylaria isolates. Commun Chem 2024; 7:129. [PMID: 38849519 PMCID: PMC11161606 DOI: 10.1038/s42004-024-01210-6] [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: 12/16/2023] [Accepted: 05/24/2024] [Indexed: 06/09/2024] Open
Abstract
Fungi constitute the Earth's second most diverse kingdom, however only a small percentage of these have been thoroughly examined and categorized for their secondary metabolites, which still limits our understanding of the ecological chemical and pharmacological potential of fungi. In this study, we explored members of the co-evolved termite-associated fungal genus Xylaria and identified a family of highly oxygenated polyketide-terpene hybrid natural products using an MS/MS molecular networking-based dereplication approach. Overall, we isolated six no yet reported xylasporin derivatives, of which xylasporin A (1) features a rare cyclic-carbonate moiety. Extensive comparative spectrometric (HRMS2) and spectroscopic (1D and 2D NMR) studies allowed to determine the relative configuration across the xylasporin family, which was supported by chemical shift calculations of more than 50 stereoisomers and DP4+ probability analyses. The absolute configuration of xylasporin A (1) was also proposed based on TDDFT-ECD calculations. Additionally, we were able to revise the relative and absolute configurations of co-secreted xylacremolide B produced by single x-ray crystallography. Comparative genomic and transcriptomic analysis allowed us to deduce the putative biosynthetic assembly line of xylasporins in the producer strain X802, and could guide future engineering efforts of the biosynthetic pathway.
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Affiliation(s)
- Seoung Rak Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- College of Pharmacy and Research Institute for Drug Development, Pusan National University, Busan, 46241, Republic of Korea
| | - Marie Dayras
- Anti-infectives from Microbiota Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) Campus E8.1, 66123, Saarbrücken, Germany
| | - Janis Fricke
- Chemical Biology of Microbe-Host Interactions Leibniz institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Beutenbergstraße 11a, 07745, Jena, Germany
| | - Huijuan Guo
- Chemical Biology of Microbe-Host Interactions Leibniz institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Beutenbergstraße 11a, 07745, Jena, Germany
| | - Sven Balluff
- Anti-infectives from Microbiota Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) Campus E8.1, 66123, Saarbrücken, Germany
| | - Felix Schalk
- Chemical Biology of Microbe-Host Interactions Leibniz institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Beutenbergstraße 11a, 07745, Jena, Germany
| | - Jae Sik Yu
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Integrative Biological Sciences and Industry, Sejong University, Seoul, 05006, Republic of Korea
| | - Se Yun Jeong
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Bernd Morgenstern
- Saarland University, Inorganic Solid-State Chemistry, Campus, Building C4 1, 66123, Saarbrücken, Germany
| | - Bernard Slippers
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Christine Beemelmanns
- Anti-infectives from Microbiota Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) Campus E8.1, 66123, Saarbrücken, Germany.
- Chemical Biology of Microbe-Host Interactions Leibniz institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Beutenbergstraße 11a, 07745, Jena, Germany.
- Saarland University, 66123, Saarbrücken, Germany.
| | - Ki Hyun Kim
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
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2
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Chen S, Zhou A, Xu Y. Symbiotic Bacteria Regulating Insect-Insect/Fungus/Virus Mutualism. INSECTS 2023; 14:741. [PMID: 37754709 PMCID: PMC10531535 DOI: 10.3390/insects14090741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 07/25/2023] [Accepted: 09/02/2023] [Indexed: 09/28/2023]
Abstract
Bacteria associated with insects potentially provide many beneficial services and have been well documented. Mutualism that relates to insects is widespread in ecosystems. However, the interrelation between "symbiotic bacteria" and "mutualism" has rarely been studied. We introduce three systems of mutualism that relate to insects (ants and honeydew-producing Hemiptera, fungus-growing insects and fungi, and plant persistent viruses and vector insects) and review the species of symbiotic bacteria in host insects, as well as their functions in host insects and the mechanisms underlying mutualism regulation. A deeper understanding of the molecular mechanisms and role of symbiotic bacteria, based on metagenomics, transcriptomics, proteomics, metabolomics, and microbiology, will be required for describing the entire interaction network.
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Affiliation(s)
- Siqi Chen
- Red Imported Fire Ant Research Center, South China Agricultural University, Guangzhou 510642, China;
| | - Aiming Zhou
- Hubei Insect Resources Utilization and Sustainable Pest Management, Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Yijuan Xu
- Red Imported Fire Ant Research Center, South China Agricultural University, Guangzhou 510642, China;
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Siddiqui SA, Fernando I, Saraswati YR, Rahayu T, Harahap IA, Yao Q, Nagdalian A, Blinov A, Shah MA. Termites as human foods-A comprehensive review. Compr Rev Food Sci Food Saf 2023; 22:3647-3684. [PMID: 37350054 DOI: 10.1111/1541-4337.13199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 05/13/2023] [Accepted: 05/29/2023] [Indexed: 06/24/2023]
Abstract
Global food production is anticipated to rise along with the growth of the global population. As a result, creative solutions must be devised to ensure that everyone has access to nutritious, affordable, and safe food. Consequently, including insects in diets has the potential to improve global food and nutrition security. This paper aims to share recent findings by covering edible termites as the main aspect, from their consumption record until consumer acceptance. A total of 53 termite species are reported as edible ones and distributed in 6 biogeographic realms. Generally, termites have a nutrient composition that is suitable for human consumption, and cooked termites are a better dietary choice than their raw counterparts. Besides, increasing customer interest in eating termite-based food can be achieved by making it more palatable and tastier through various cooking processes, that is, boiling, frying, grilling, roasting, smoking, and sun-drying. Moreover, edible termites can also be used as a new source of medication by exhibiting antimicrobial activity. Regarding their advantages, it is strongly encouraged to implement a seminatural rearing system to sustain the supply of edible termites. Overall, this paper makes it evident that termites are an important natural resource for food or medicine. Hence, the long-term objective is to stimulate scientific inquiry into the potential of edible insects as an answer to the problem of global food security.
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Affiliation(s)
- Shahida Anusha Siddiqui
- Technical University of Munich, Department of Biotechnology and Sustainability, Straubing, Germany
- German Institute of Food Technologies (DIL e.V.), D-Quakenbrueck, Germany
| | - Ito Fernando
- Department of Plant Pest and Diseases, Faculty of Agriculture, Universitas Brawijaya, Malang, East Java, Indonesia
| | - Yuniar Rizky Saraswati
- School of Agriculture, Food and Ecosystem Sciences, Faculty of Science, The University of Melbourne, Melbourne, Victoria, Australia
| | - Teguh Rahayu
- CV HermetiaTech, Surabaya, Jawa Timur, Indonesia
| | | | - Qifa Yao
- Insect Engineers, Melderslo, The Netherlands
| | - Andrey Nagdalian
- Department of Food Technology and Engineering, Faculty of Food Engineering and Biotechnology, North-Caucasus Federal University, Stavropol, Russia
| | - Andrey Blinov
- Department of Food Technology and Engineering, Faculty of Food Engineering and Biotechnology, North-Caucasus Federal University, Stavropol, Russia
| | - Mohd Asif Shah
- Department of Economics, Kabridahar University, Kabridahar, Somali, Ethiopia
- School of Business, Woxsen University, Hyderabad, Telangana, India
- Division of Research and Development, Lovely Professional University, Phagwara, Punjab, India
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4
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Kreuzenbeck NB, Dhiman S, Roman D, Burkhardt I, Conlon BH, Fricke J, Guo H, Blume J, Görls H, Poulsen M, Dickschat JS, Köllner TG, Arndt HD, Beemelmanns C. Isolation, (bio)synthetic studies and evaluation of antimicrobial properties of drimenol-type sesquiterpenes of Termitomyces fungi. Commun Chem 2023; 6:79. [PMID: 37095327 PMCID: PMC10126200 DOI: 10.1038/s42004-023-00871-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 03/29/2023] [Indexed: 04/26/2023] Open
Abstract
Macrotermitinae termites have farmed fungi in the genus Termitomyces as a food source for millions of years. However, the biochemical mechanisms orchestrating this mutualistic relationship are largely unknown. To deduce fungal signals and ecological patterns that relate to the stability of this symbiosis, we explored the volatile organic compound (VOC) repertoire of Termitomyces from Macrotermes natalensis colonies. Results show that mushrooms emit a VOC pattern that differs from mycelium grown in fungal gardens and laboratory cultures. The abundance of sesquiterpenoids from mushrooms allowed targeted isolation of five drimane sesquiterpenes from plate cultivations. The total synthesis of one of these, drimenol, and related drimanes assisted in structural and comparative analysis of volatile organic compounds (VOCs) and antimicrobial activity testing. Enzyme candidates putatively involved in terpene biosynthesis were heterologously expressed and while these were not involved in the biosynthesis of the complete drimane skeleton, they catalyzed the formation of two structurally related monocyclic sesquiterpenes named nectrianolins.
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Affiliation(s)
- Nina B Kreuzenbeck
- Chemical Biology of Microbe-Host Interactions, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll-Institute (HKI), Beutenbergstraße 11a, 07745, Jena, Germany
| | - Seema Dhiman
- Institute for Organic and Macromolecular Chemistry, Friedrich-Schiller-University Jena, Humboldtstr. 10, 07743, Jena, Germany
| | - Dávid Roman
- Chemical Biology of Microbe-Host Interactions, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll-Institute (HKI), Beutenbergstraße 11a, 07745, Jena, Germany
| | - Immo Burkhardt
- Kekulé-Institute of Organic Chemistry and Biochemistry, University of Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Benjamin H Conlon
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15 2100, Copenhagen, Denmark
| | - Janis Fricke
- Chemical Biology of Microbe-Host Interactions, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll-Institute (HKI), Beutenbergstraße 11a, 07745, Jena, Germany
| | - Huijuan Guo
- Chemical Biology of Microbe-Host Interactions, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll-Institute (HKI), Beutenbergstraße 11a, 07745, Jena, Germany
| | - Janis Blume
- Institute for Organic and Macromolecular Chemistry, Friedrich-Schiller-University Jena, Humboldtstr. 10, 07743, Jena, Germany
| | - Helmar Görls
- Institute for Inorganic and Analytical Chemistry, Friedrich-Schiller University, Humboldtstrasse 8, 07743, Jena, Germany
| | - Michael Poulsen
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15 2100, Copenhagen, Denmark
| | - Jeroen S Dickschat
- Kekulé-Institute of Organic Chemistry and Biochemistry, University of Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Tobias G Köllner
- Department of Natural Product Biosynthesis, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745, Jena, Germany
| | - Hans-Dieter Arndt
- Institute for Organic and Macromolecular Chemistry, Friedrich-Schiller-University Jena, Humboldtstr. 10, 07743, Jena, Germany
| | - Christine Beemelmanns
- Chemical Biology of Microbe-Host Interactions, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll-Institute (HKI), Beutenbergstraße 11a, 07745, Jena, Germany.
- Helmholtz-Institut für Pharmazeutische Forschung Saarland (HIPS), Helmholtz Zentrum für Infektionsforschung (HZI), Campus E8.1, 66123, Saarbrücken, Germany.
- Universität des Saarlandes, Campus E8, 66123, Saarbrücken, Germany.
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Vreeburg SME, Auxier B, Jacobs B, Bourke PM, van den Heuvel J, Zwaan BJ, Aanen DK. A genetic linkage map and improved genome assembly of the termite symbiont Termitomyces cryptogamus. BMC Genomics 2023; 24:123. [PMID: 36927388 PMCID: PMC10021994 DOI: 10.1186/s12864-023-09210-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 02/27/2023] [Indexed: 03/18/2023] Open
Abstract
BACKGROUND The termite-fungus symbiosis is an ancient stable mutualism of two partners that reproduce and disperse independently. With the founding of each termite colony the symbiotic association must be re-established with a new fungus partner. Complementarity in the ability to break down plant substrate may help to stabilize this symbiosis despite horizontal symbiont transmission. An alternative, non-exclusive, hypothesis is that a reduced rate of evolution may contribute to stabilize the symbiosis, the so-called Red King Effect. METHODS To explore this concept, we produced the first linkage map of a species of Termitomyces, using genotyping by sequencing (GBS) of 88 homokaryotic offspring. We constructed a highly contiguous genome assembly using PacBio data and a de-novo evidence-based annotation. This improved genome assembly and linkage map allowed for examination of the recombination landscape and its potential effect on the mutualistic lifestyle. RESULTS Our linkage map resulted in a genome-wide recombination rate of 22 cM/Mb, lower than that of other related fungi. However, the total map length of 1370 cM was similar to that of other related fungi. CONCLUSIONS The apparently decreased rate of recombination is primarily due to genome expansion of islands of gene-poor repetitive sequences. This study highlights the importance of inclusion of genomic context in cross-species comparisons of recombination rate.
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Affiliation(s)
- Sabine M E Vreeburg
- Laboratory of Genetics, Wageningen University & Research, Wageningen, the Netherlands
| | - Ben Auxier
- Laboratory of Genetics, Wageningen University & Research, Wageningen, the Netherlands.
| | - Bas Jacobs
- Laboratory of Genetics, Wageningen University & Research, Wageningen, the Netherlands.,Biometris, Wageningen University & Research, Wageningen, the Netherlands
| | - Peter M Bourke
- Plant Breeding, Wageningen University & Research, Wageningen, the Netherlands
| | - Joost van den Heuvel
- Laboratory of Genetics, Wageningen University & Research, Wageningen, the Netherlands
| | - Bas J Zwaan
- Laboratory of Genetics, Wageningen University & Research, Wageningen, the Netherlands
| | - Duur K Aanen
- Laboratory of Genetics, Wageningen University & Research, Wageningen, the Netherlands
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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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Diehl JMC, Keller A, Biedermann PHW. Comparing the succession of microbial communities throughout development in field and laboratory nests of the ambrosia beetle Xyleborinus saxesenii. Front Microbiol 2023; 14:1151208. [PMID: 37152720 PMCID: PMC10159272 DOI: 10.3389/fmicb.2023.1151208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 03/31/2023] [Indexed: 05/09/2023] Open
Abstract
Some fungus-farming ambrosia beetles rely on multiple nutritional cultivars (Ascomycota: Ophiostomatales and/or yeasts) that seem to change in relative abundance over time. The succession of these fungi could benefit beetle hosts by optimal consumption of the substrate and extended longevity of the nest. However, abundances of fungal cultivars and other symbionts are poorly known and their culture-independent quantification over development has been studied in only a single species. Here, for the first time, we compared the diversity and succession of both fungal and bacterial communities of fungus gardens in the fruit-tree pinhole borer, Xyleborinus saxesenii, from field and laboratory nests over time. By amplicon sequencing of probed fungus gardens of both nest types at three development phases we showed an extreme reduction of diversity in both bacterial and fungal symbionts in laboratory nests. Furthermore, we observed a general transition from nutritional to non-beneficial fungal symbionts during beetle development. While one known nutritional mutualist, Raffaelea canadensis, was occurring more or less stable over time, the second mutualist R. sulphurea was dominating young nests and decreased in abundance at the expense of other secondary fungi. The quicker the succession proceeded, the slower offspring beetles developed, suggesting a negative role of these secondary symbionts. Finally, we found signs of transgenerational costs of late dispersal for daughters, possibly as early dispersers transmitted and started their own nests with less of the non-beneficial taxa. Future studies should focus on the functional roles of the few bacterial taxa that were present in both field and laboratory nests.
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Affiliation(s)
- Janina M. C. Diehl
- Chair of Forest Entomology and Protection, Institute of Forestry, University of Freiburg, Freiburg im Breisgau, Germany
- Insect-Fungus Interactions Research Group, Department of Animal Ecology and Tropical Biology, University of Würzburg, Würzburg, Germany
- *Correspondence: Janina M. C. Diehl,
| | - Alexander Keller
- Faculty of Biology, Cellular and Organismic Networks, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Peter H. W. Biedermann
- Chair of Forest Entomology and Protection, Institute of Forestry, University of Freiburg, Freiburg im Breisgau, Germany
- Peter H. W. Biedermann,
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Tharavecharak S, D’Alessandro-Gabazza CN, Toda M, Yasuma T, Tsuyama T, Kamei I, Gabazza EC. Culture Conditions for Mycelial Growth and Anti-Cancer Properties of Termitomyces. MYCOBIOLOGY 2023; 51:94-108. [PMID: 37122680 PMCID: PMC10142329 DOI: 10.1080/12298093.2023.2187614] [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] [Indexed: 05/03/2023]
Abstract
Termitomyces sp. that grow in symbiosis with fungus-farming Termites have medicinal properties. However, they are rare in nature, and their artificial culture is challenging. The expression of AXL receptor tyrosine kinase and immune checkpoint molecules favor the growth of cancer cells. The study evaluated the optimal conditions for the artificial culture of Termitomyces and their inhibitory activity on AXL and immune checkpoint molecules in lung adenocarcinoma and melanoma cell lines. The culture of 45 strains of Termitomyces was compared. Five strains with marked growth rates were selected. Four of the selected strains form a single cluster by sequence analysis. The mycelium of 4 selected strains produces more fungal mass in potato dextrose broth than in a mixed media. The bark was the most appropriate solid substrate for Termitomyces mycelia culture. The mycelium of all five selected strains showed a higher growth rate under normal CO2 conditions. The culture broth, methanol, and ethyl acetate of one selected strain (T-120) inhibited the mRNA relative expression of AXL receptor tyrosine kinase and immune checkpoint molecules in cancer cell lines. Overall, these results suggest the potential usefulness of Termitomyces extracts as a co-adjuvant therapy in malignant diseases.
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Affiliation(s)
- Suphachai Tharavecharak
- Graduate School of Agriculture, University of Miyazaki, Miyazaki, Japan
- Department of Immunology, Faculty of Medicine, Graduate School of Medicine, Mie University, Tsu, Japan
| | | | - Masaaki Toda
- Department of Immunology, Faculty of Medicine, Graduate School of Medicine, Mie University, Tsu, Japan
| | - Taro Yasuma
- Department of Immunology, Faculty of Medicine, Graduate School of Medicine, Mie University, Tsu, Japan
| | - Taku Tsuyama
- Graduate School of Agriculture, University of Miyazaki, Miyazaki, Japan
| | - Ichiro Kamei
- Graduate School of Agriculture, University of Miyazaki, Miyazaki, Japan
| | - Esteban C. Gabazza
- Department of Immunology, Faculty of Medicine, Graduate School of Medicine, Mie University, Tsu, Japan
- CONTACT Esteban C. Gabazza
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Ahmad F, Yang G, Zhu Y, Poulsen M, Li W, Yu T, Mo J. Tripartite Symbiotic Digestion of Lignocellulose in the Digestive System of a Fungus-Growing Termite. Microbiol Spectr 2022; 10:e0123422. [PMID: 36250871 PMCID: PMC9769757 DOI: 10.1128/spectrum.01234-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 09/23/2022] [Indexed: 01/05/2023] Open
Abstract
Fungus-growing termites are efficient in degrading and digesting plant substrates, achieved through the engagement of symbiotic gut microbiota and lignocellulolytic Termitomyces fungi cultivated for protein-rich food. Insights into where specific plant biomass components are targeted during the decomposition process are sparse. In this study, we performed several analytical approaches on the fate of plant biomass components and did amplicon sequencing of the 16S rRNA gene to investigate the lignocellulose digestion in the symbiotic system of the fungus-growing termite Odontotermes formosanus (Shiraki) and to compare bacterial communities across the different stages in the degradation process. We observed a gradual reduction of lignocellulose components throughout the process. Our findings support that the digestive tract of young workers initiates the degradation of lignocellulose but leaves most of the lignin, hemicellulose, and cellulose, which enters the fresh fungus comb, where decomposition primarily occurs. We found a high diversity and quantity of monomeric sugars in older parts of the fungus comb, indicating that the decomposition of lignocellulose enriches the old comb with sugars that can be utilized by Termitomyces and termite workers. Amplicon sequencing of the 16S rRNA gene showed clear differences in community composition associated with the different stages of plant biomass decomposition which could work synergistically with Termitomyces to shape the digestion process. IMPORTANCE Fungus-farming termites have a mutualist association with fungi of the genus Termitomyces and gut microbiota to support the nearly complete decomposition of lignocellulose to gain access to nutrients. This elaborate strategy of plant biomass digestion makes them ecologically successful dominant decomposers in (sub)tropical Old World ecosystems. We employed acid detergent fiber analysis, high-performance anion-exchange chromatography (HPAEC), high-performance liquid chromatography (HPLC), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), pyrolysis gas chromatography-mass spectrometry (Py-GC-MS), and amplicon sequencing of the 16S rRNA gene to examine which lignocellulose components were digested and which bacteria were abundant throughout the decomposition process. Our findings suggest that although the first gut passage initiates lignocellulose digestion, the most prominent decomposition occurs within the fungus comb. Moreover, distinct bacterial communities were associated with different stages of decomposition, potentially contributing to the breakdown of particular plant components.
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Affiliation(s)
- Farhan Ahmad
- Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Zhejiang, People’s Republic of China
- Entomology Section, Central Cotton Research Institute, Multan, Punjab, Pakistan
- Entomology Section, Central Cotton Research Institute, Sakrand, Shaheed Benazirabad, Sindh, Pakistan
| | - Guiying Yang
- Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Zhejiang, People’s Republic of China
| | - Yaning Zhu
- Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Zhejiang, People’s Republic of China
| | - Michael Poulsen
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen East, Denmark
| | - Wuhan Li
- Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Zhejiang, People’s Republic of China
| | - Ting Yu
- Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Zhejiang, People’s Republic of China
| | - Jianchu Mo
- Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Zhejiang, People’s Republic of China
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Comparative Genomic and Metabolomic Analysis of Termitomyces Species Provides Insights into the Terpenome of the Fungal Cultivar and the Characteristic Odor of the Fungus Garden of Macrotermes natalensis Termites. mSystems 2022; 7:e0121421. [PMID: 35014870 PMCID: PMC8751386 DOI: 10.1128/msystems.01214-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Macrotermitinae termites have domesticated fungi of the genus Termitomyces as food for their colony, analogously to human farmers growing crops. Termites propagate the fungus by continuously blending foraged and predigested plant material with fungal mycelium and spores (fungus comb) within designated subterranean chambers. To test the hypothesis that the obligate fungal symbiont emits specific volatiles (odor) to orchestrate its life cycle and symbiotic relations, we determined the typical volatile emission of fungus comb biomass and Termitomyces nodules, revealing α-pinene, camphene, and d-limonene as the most abundant terpenes. Genome mining of Termitomyces followed by gene expression studies and phylogenetic analysis of putative enzymes related to secondary metabolite production encoded by the genomes uncovered a conserved and specific biosynthetic repertoire across strains. Finally, we proved by heterologous expression and in vitro enzymatic assays that a highly expressed gene sequence encodes a rare bifunctional mono-/sesquiterpene cyclase able to produce the abundant comb volatiles camphene and d-limonene. IMPORTANCE The symbiosis between macrotermitinae termites and Termitomyces is obligate for both partners and is one of the most important contributors to biomass conversion in the Old World tropic’s ecosystems. To date, research efforts have dominantly focused on acquiring a better understanding of the degradative capabilities of Termitomyces to sustain the obligate nutritional symbiosis, but our knowledge of the small-molecule repertoire of the fungal cultivar mediating interspecies and interkingdom interactions has remained fragmented. Our omics-driven chemical, genomic, and phylogenetic study provides new insights into the volatilome and biosynthetic capabilities of the evolutionarily conserved fungal genus Termitomyces, which allows matching metabolites to genes and enzymes and, thus, opens a new source of unique and rare enzymatic transformations.
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Isolation, identification, cultivation and determination of antimicrobial β-glucan from a wild-termite mushroom Termitomyces heimii RFES 230662. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2021. [DOI: 10.1016/j.bcab.2021.102187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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The Termite Fungal Cultivar Termitomyces Combines Diverse Enzymes and Oxidative Reactions for Plant Biomass Conversion. mBio 2021; 12:e0355120. [PMID: 34126770 PMCID: PMC8262964 DOI: 10.1128/mbio.03551-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Macrotermitine termites have domesticated fungi in the genus Termitomyces as their primary food source using predigested plant biomass. To access the full nutritional value of lignin-enriched plant biomass, the termite-fungus symbiosis requires the depolymerization of this complex phenolic polymer. While most previous work suggests that lignocellulose degradation is accomplished predominantly by the fungal cultivar, our current understanding of the underlying biomolecular mechanisms remains rudimentary. Here, we provide conclusive omics and activity-based evidence that Termitomyces employs not only a broad array of carbohydrate-active enzymes (CAZymes) but also a restricted set of oxidizing enzymes (manganese peroxidase, dye decolorization peroxidase, an unspecific peroxygenase, laccases, and aryl-alcohol oxidases) and Fenton chemistry for biomass degradation. We propose for the first time that Termitomyces induces hydroquinone-mediated Fenton chemistry (Fe2+ + H2O2 + H+ → Fe3+ + •OH + H2O) using a herein newly described 2-methoxy-1,4-dihydroxybenzene (2-MH2Q, compound 19)-based electron shuttle system to complement the enzymatic degradation pathways. This study provides a comprehensive depiction of how efficient biomass degradation by means of this ancient insect’s agricultural symbiosis is accomplished.
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de Paula GT, Menezes C, Pupo MT, Rosa CA. Stingless bees and microbial interactions. CURRENT OPINION IN INSECT SCIENCE 2021; 44:41-47. [PMID: 33271364 DOI: 10.1016/j.cois.2020.11.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 10/30/2020] [Accepted: 11/17/2020] [Indexed: 06/12/2023]
Abstract
Stingless bees (Meliponini) are a monophyletic group of eusocial insects inhabiting tropical and subtropical regions. These insects represent the most abundant and diversified group of corbiculate bees. Meliponini mostly rely on fermentation by symbiont microbes to preserve honey and transform pollen in stored food. Bee nests harbor diverse microbiota that includes bacteria, yeasts, filamentous fungi, and viruses. These microorganisms may interact with the bees through symbiotic relationships, or they may act as food for the insects, or produce biomolecules that aid in the biotransformation of bee products, such as honey and bee bread. Certain microbial species can also produce antimicrobial compounds that inhibit opportunistic bee pathogens.
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Affiliation(s)
- Gabriela Toninato de Paula
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, 14040-903 Ribeirão Preto, SP, Brazil
| | - Cristiano Menezes
- Brazilian Agricultural Research Corporation, Embrapa Meio Ambiente, Jaguariúna, SP, Brazil
| | - Mônica Tallarico Pupo
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, 14040-903 Ribeirão Preto, SP, Brazil
| | - Carlos Augusto Rosa
- Departamento de Microbiologia, ICB, C.P. 486, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil.
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Korb J, Silué SK, Koné NA. Can Differences in Symbiont Transmission Mode Explain the Abundance and Distribution of Fungus-Growing Termites in West Africa? Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.600318] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Fungus-growing termites (Isoptera: Macrotermitinae) dominate African savannah ecosystems where they play important roles in ecosystem functioning. Their ecological dominance in these ecosystems has been attributed to living in an ectosymbiosis with fungi of the genus Termitomyces (Lyophyllaceae). Evolutionary theory predicts that the transmission mode of a symbiont determines cooperation and conflict between host and symbiont with vertical transmission (co-transmission of host and symbiont offspring to the next generation) leading to less conflict than horizontal transmission (symbionts are acquired by the host from the environment). Thus, one can hypothesize associations with vertical transmission to be ecological more successful than those with horizontal transmission. We tested this by analyzing whether there is an association between transmission mode and fungus-growing termite species abundance and distribution in West-African savannah and forest ecosystems. We used data from a total of 78 study sites comprising protected National Parks as well as anthropogenically disturbed ecosystems, covering Benin, Côte d'Ivoire, and Togo. Our results showed that, in contrast to expectation, species with horizontal symbiont transmission were more common. We encountered more often species with horizontal than vertical transmission. This result might be due to the fact that only five out of the 25 identified fungus-growing termite species had vertical transmission. Yet, species with horizontal transmission also had higher relative abundances within study sites than those with vertical transmission. Thus, transmission mode is unlikely to explain abundance differences between fungus-growing termite species.
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