Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 89
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
BMC Genomics ; 24(1): 123, 2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36927388

RESUMO

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.


Assuntos
Isópteros , Termitomyces , Animais , Isópteros/genética , Isópteros/microbiologia , Termitomyces/genética , Fungos/genética , Genômica , Simbiose/genética , Ligação Genética
2.
Microsc Res Tech ; 86(1): 115-121, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36404727

RESUMO

Termitomyces pakistanensis sp. nov. is a member of an edible genus generally distributed in Asia and Europe. This species has been described as new species based on its different morphology, and scanning electron microscopy (SEM) of basidiospores. The novelty and degree of endemism is confirmed by analyzing the genetic variation of the internal transcribed spacer regions (ITS1-5.8 S-ITS2) of the ribosomal DNA gene, a universal fungal marker. The evolutionary affinities of new species is also evaluated with Asian and European species by phylogenetic analysis based on ITS sequences. In our phylogenetic analysis, this genus is found monophyletic comprising of two monophyletic sub clades: Clade I, Microcarpus, with small sized fruiting bodies generally less than 5 cm without pseudorrhiza and Clade II, Macrocarpus, with large sized fruiting bodies generally more than 5 cm having pseudorrhiza. All collections of Pakistani species clustered independently in Microcarpus clade showing their endemic genetic makeup as it is clustering independently. A comprehensive description, photographs of the basidiocarps and Scanning electron microscopy (SEM) micrographs of spores are provided. RESEARCH HIGHLIGHTS: It has a new species from Pakistan to world based on the scanning electron microscopy and further confirmed by DNA barcoding. The exact shape and size of basidiospores of this novel species is first time introduced by using SEM analysis. This genus is rarely described from Pakistan. This paper has introduced a two clade, Microcarpus and macrocarpus, in the world for this genus.


Assuntos
Agaricales , Basidiomycota , Termitomyces , DNA Ribossômico/genética , Agaricales/genética , Microscopia Eletrônica de Varredura , Termitomyces/genética , Paquistão , Filogenia , DNA Espaçador Ribossômico/genética , DNA Fúngico/genética , Basidiomycota/genética , Esporos Fúngicos/genética , Análise de Sequência de DNA
3.
Biosystems ; 221: 104763, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36029916

RESUMO

Fungus-cultivating termite Odontotermes badius developed a mutualistic association with Termitomyces fungi for the plant material decomposition and providing a food source for the host survival. The mutualistic relationship sifted the microbiome composition of the termite gut and Termitomyces fungal comb. Symbiotic bacterial communities in the O. badius gut and fungal comb have been studied extensively to identify abundant bacteria and their lignocellulose degradation capabilities. Despite several metagenomic studies, the species-wide metabolic interaction patterns of bacterial communities in termite gut and fungal comb remains unclear. The bacterial species metabolic interaction network (BSMIN) has been constructed with 230 bacteria identified from the O. badius gut and fungal comb microbiota. The network portrayed the metabolic map of the entire microbiota and highlighted several inter-species biochemical interactions like cross-feeding, metabolic interdependency, and competition. Further, the reconstruction and analysis of the bacterial influence network (BIN) quantified the positive and negative pairwise influences in the termite gut and fungal comb microbial communities. Several key macromolecule degraders and fermentative microbial entities have been identified by analyzing the BIN. The mechanistic interplay between these influential microbial groups and the crucial glycoside hydrolases (GH) enzymes produced by the macromolecule degraders execute the community-wide functionality of lignocellulose degradation and subsequent fermentation. The metabolic interaction pattern between the nine influential microbial species has been determined by considering them growing in a synthetic microbial community. Competition (30%), parasitism (47%), and mutualism (17%) were predicted to be the major mode of metabolic interaction in this synthetic microbial community. Further, the antagonistic metabolic effect was found to be very high in the metabolic-deprived condition, which may disrupt the community functionality. Thus, metabolic interactions of the crucial bacterial species and their GH enzyme cocktail identified from the O. badius gut and fungal comb microbiota may provide essential knowledge for developing a synthetic microcosm with efficient lignocellulolytic machinery.


Assuntos
Microbioma Gastrointestinal , Isópteros , Termitomyces , Animais , Bactérias , Glicosídeo Hidrolases/metabolismo , Isópteros/metabolismo , Isópteros/microbiologia
4.
mSystems ; 7(1): e0121421, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35014870

RESUMO

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.


Assuntos
Isópteros , Termitomyces , Animais , Humanos , Termitomyces/genética , Filogenia , Ecossistema , Limoneno/metabolismo , Odorantes , Genômica
5.
Lett Appl Microbiol ; 74(3): 429-443, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34890484

RESUMO

The edible mushroom Termitomyces is an agaric-type basidiomycete fungus that has a symbiotic relationship with fungus-growing termites. An understanding of the detailed development mechanisms underlying the adaptive responses of Termitomyces sp. to their growing environment is lacking. Here, we compared the transcriptome sequences of different Termitomyces sp. samples and link-stipe grown on fungus combs in situ and monocultured in vitro. The assembled reads generated 8052 unigenes. The expression profiles were highly different for 2556 differentially expressed genes (DEGs) of the treated samples, where the expression of 1312 and 1244 DEGs was upregulated in the Mycelium and link-stipe groups respectively. Functional classification of the DEGs based on both Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed an expected shift in fungal gene expression, where stress response genes whose expression was upregulated in link-stipe may adaptively be involved in cell wall hydrolysis and fusion, pathogenesis, oxidation-reduction, transporter efflux, transposon efflux and self/non-self-recognition. Urease has implications in the expression of genes involved in the nitrogen metabolism pathway, and its expression could be controlled by low-level nitrogen fixation of fungus combs. In addition, the expression patterns of eleven select genes on the basis of qRT-PCR were consistent with their changes in transcript abundance, as revealed by RNA sequencing. Taken together, these findings may be useful for enriching the knowledge concerning the Termitomyces adaptive response to in situ fungus combs compared with the response of monocultures in vitro.


Assuntos
Agaricales , Isópteros , Termitomyces , Animais , Perfilação da Expressão Gênica , Simbiose , Transcriptoma
6.
J Agric Food Chem ; 70(1): 21-33, 2022 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-34936332

RESUMO

Termitomyces are well-known wild edible and medicinal basidiomycete mushrooms. The frequent consumption of Termitomyces stimulated studies on their health-promoting properties. Numerous health benefits of Termitomyces are associated with the main categories of components in Termitomyces, polysaccharides. Although the homopolysaccharides ß-glucans are believed to be the major bioactive polysaccharides of Termitomyces, other heteropolysaccharides also possess biological activities. In this review, the extraction methods, chemical structures, and biological activities of polysaccharides from Termitomyces were thoroughly reviewed. The polysaccharides from different species of Termitomyces differ in molecular weight, monosaccharide composition, and linkages of constituent sugars. The health-promoting effects, including antioxidation, ulcer-healing and analgesic properties, immunomodulation, hypolipidemic and hepatoprotective effects, and antidiabetic properties of Termitomyces polysaccharides were summarized and discussed. Further studies were needed for a better understanding of the relationship between the fine chemical structure and health-promoting properties. This review provides a theoretical overview for future studies and utilization of Termitomyces polysaccharides.


Assuntos
Agaricales , Basidiomycota , Termitomyces , beta-Glucanas , Polissacarídeos
7.
Nat Prod Res ; 36(18): 4681-4691, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34878952

RESUMO

Termitomyces species are known edible mushrooms in Nigeria, believed to have exceptional culinary and nutraceutical properties. Methanol extract from fruiting bodies of Termitomyces robustus was evaluated for antidiabetic activity using in vitro α-amylase and α-glucosidase assays. The isolation and structural elucidation of metabolites from the T. robustus extract afforded five compounds including a new natural product γ-glutamyl-ß-phenylethylamine 3 and four known phenyl derivatives: tryptophan 1, 4-hydroxyphenylacetic acid 2, 4-hydroxyphenylpropionic acid 4, and phenyllactic acid 5. Structures were elucidated from analyses of spectroscopic data (1 D and 2 D NMR, HRESIMS) and all isolated compounds were tested for α-amylase and α-glycosidase inhibitory activity. The in vitro assay established crude extract to possess α- amylase and α-glucosidase inhibition with IC50 of 78.05 µg/mL and 86.10 µg/mL, respectively. The isolated compounds compared favourably with the standard drug, acarbose with IC50 ranging from 6.18-15.08 µg/mL and 18.28-44.63 µg/mL for α-amylase and glucosidase, respectively.


Assuntos
Agaricales , Termitomyces , Agaricales/metabolismo , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Nigéria , Fenetilaminas , Extratos Vegetais/química , Termitomyces/metabolismo , alfa-Amilases , alfa-Glucosidases/metabolismo
8.
Int J Med Mushrooms ; 23(9): 85-94, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34591401

RESUMO

Termitomyces albuminosus, also known as termite mushroom, is a palatable mushroom with therapeutic effects that has been used as a food and folk medicinal ingredient. Recent studies revealed that T. albuminosus contains pharmacologically active factors that exert anti-inflammatory, antihyperlipidemic, antidiabetic, hepatoprotective, and neuritogenic activities, leading to its increasing popularity as a supplement among the general public. Despite the increase in its use, however, lack of knowledge on the toxicity of T. albuminosus has raised safety concerns. In this study, we systemically evaluated the genotoxicity of T. albuminosus powder (TAP) by testing its potential in generating bacterial reverse mutation, in vitro chromosome aberration, and in vivo micronuclei. TAP did not increase revertant colonies in the bacterial reverse mutation test nor the number of cells with aberrant chromosomes at 5000 µg/plate and micronucleus-containing polychromatic erythrocytes at 2000 mg/kg body weight in mice, indicating that TAP is not mutagenic nor clastogenic. Our results, together with the previous data from the general toxicity studies, indicate that TAP is safe for human consumption.


Assuntos
Agaricales , Isópteros , Termitomyces , Animais , Camundongos , Testes de Mutagenicidade , Pós
9.
Mycologia ; 113(6): 1199-1217, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34477494

RESUMO

The Ophiostomatales (Ascomycota) accommodates more than 300 species characterized by similar morphological adaptations to arthropod dispersal. Most species in this order are wood-inhabiting fungi associated with bark or ambrosia beetles. However, a smaller group of species occur in other niches such as in soil and Protea infructescences. Recent surveys of Termitomyces fungus gardens (fungus combs) of fungus-growing termites led to the discovery of characteristic ophiostomatalean-like fruiting structures. In this study, these ophiostomatalean-like fungi were identified using morphological characteristics, conventional molecular markers, and whole genome sequencing. In addition, the influence of the extracts derived from various parts of Termitomyces combs on the growth of these fungi in culture was considered. Based on phylogenomic analyses, two new genera (Intubia and Chrysosphaeria) were introduced to accommodate these ophiostomatalean species. Phylogenetic analyses revealed that the isolates resided in three well-supported lineages, and these were described as three new species (Intubia macrotermitinarum, I. oerlemansii, and Chrysosphaeria jan-nelii). Culture-based studies showed that these species do not depend on the Termitomyces comb material for growth.


Assuntos
Isópteros , Ophiostomatales , Termitomyces , Animais , Fungos , Isópteros/genética , Isópteros/microbiologia , Ophiostomatales/genética , Filogenia , Simbiose , Termitomyces/genética
10.
J Agric Food Chem ; 69(34): 9991-10001, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34410111

RESUMO

Mushroom, as a kind of higher fungus, is a precious homology resource of medicine and foods. In this study, total lipids were extracted from eight wild edible mushrooms and subsequently characterized by ultra-high-performance liquid chromatography-Quadrupole-Exactive Orbitrap mass spectrometry. 20 lipid classes and 173 molecular species were identified and quantified. Lipid molecules and their concentrations in Boletus speciosus, Boletus bainiugan, and Tricholoma matsutake exhibited significantly different behaviors compared with the remaining mushrooms. Hierarchical cluster analysis revealed that lipid profiles of B. bainiugan were most similar to B. speciosus followed by T. matsutake, Canthar-ellus cibarius, Sarcodon aspratu, Termitomyces eurrhizus, Laccaria laccata, and Thelephora ganbajun. In addition, several differential lipids can be considered as potential biomarkers to distinguish different mushroom species, for instance, lysophosphatidylethanolamine (16:1) and ceramide non-hydroxy fatty acid-dihydrosphingosine (d23:0-10:0). This study provided a new perspective to discriminate the mushroom species from the perspective of lipidomics.


Assuntos
Agaricales , Lipidômica , Basidiomycota , Laccaria , Análise de Componente Principal , Termitomyces
11.
Curr Biol ; 31(19): 4413-4421.e5, 2021 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-34403645

RESUMO

The ancestor of termites relied on gut symbionts for degradation of plant material, an association that persists in all termite families.1,2 However, the single-lineage Macrotermitinae has additionally acquired a fungal symbiont that complements digestion of food outside the termite gut.3 Phylogenetic analysis has shown that fungi grown by these termites form a clade-the genus Termitomyces-but the events leading toward domestication remain unclear.4 To address this, we reconstructed the lifestyle of the common ancestor of Termitomyces using a combination of ecological data with a phylogenomic analysis of 21 related non-domesticated species and 25 species of Termitomyces. We show that the closely related genera Blastosporella and Arthromyces also contain insect-associated species. Furthermore, the genus Arthromyces produces asexual spores on the mycelium, which may facilitate insect dispersal when growing on aggregated subterranean fecal pellets of a plant-feeding insect. The sister-group relationship between Arthromyces and Termitomyces implies that insect association and asexual sporulation, present in both genera, preceded the domestication of Termitomyces and did not follow domestication as has been proposed previously. Specialization of the common ancestor of these two genera on an insect-fecal substrate is further supported by similar carbohydrate-degrading profiles between Arthromyces and Termitomyces. We describe a set of traits that may have predisposed the ancestor of Termitomyces toward domestication, with each trait found scattered in related taxa outside of the termite-domesticated clade. This pattern indicates that the origin of the termite-fungus symbiosis may not have required large-scale changes of the fungal partner.


Assuntos
Agaricales , Isópteros , Termitomyces , Animais , Humanos , Isópteros/microbiologia , Estilo de Vida , Filogenia , Simbiose , Termitomyces/genética
12.
mBio ; 12(3): e0355120, 2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34126770

RESUMO

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. IMPORTANCE Fungus-growing termites have optimized the decomposition of recalcitrant plant biomass to access valuable nutrients by engaging in a tripartite symbiosis with complementary contributions from a fungal mutualist and a codiversified gut microbiome. This complex symbiotic interplay makes them one of the most successful and important decomposers for carbon cycling in Old World ecosystems. To date, most research has focused on the enzymatic contributions of microbial partners to carbohydrate decomposition. Here, we provide genomic, transcriptomic, and enzymatic evidence that Termitomyces also employs redox mechanisms, including diverse ligninolytic enzymes and a Fenton chemistry-based hydroquinone-catalyzed lignin degradation mechanism, to break down lignin-rich plant material. Insights into these efficient decomposition mechanisms reveal new sources of efficient ligninolytic agents applicable for energy generation from renewable sources.


Assuntos
Biomassa , Isópteros/microbiologia , Lignina/metabolismo , Estresse Oxidativo , Termitomyces/enzimologia , Termitomyces/metabolismo , Animais , Ecossistema , Microbioma Gastrointestinal , Perfilação da Expressão Gênica , Genoma Fúngico , Oxirredução , Plantas/metabolismo , Plantas/microbiologia , Simbiose , Termitomyces/classificação , Termitomyces/genética
13.
Carbohydr Res ; 505: 108333, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34000638

RESUMO

Enzymatic degradation of hemi-cellulosic substrates has gained plenty of industrial attentions recently. Complete enzymatic degradation of complex and recalcitrant hemicellulose requires an enzymatic cocktail consisting primarily of endo-1,4-ß-xylanase (xyl), ß-xylosidase, arabinofuranosidase etc. This article reports, for the first time, the identification, cloning, expression and partial characterization of a potent endo-1,4- ß-xylanase gene (pxyl) from the mushroom Termitomyces clypeatus (TC) in E. coli and S. cerevisiae. The cDNA for pxyl was found to be 678 bp that in turn gives rise to a precursor protein (Pxyl) of 225 amino acids long when cloned in prokaryotic expression vector. To characterize additionally, the cDNA was also expressed in S. cerevisiae. Bioinformatics study predicted that the Pxyl contains a 19 amino acid long leader peptide that enables post translational modifications including glycosylation as well as its efficient secretion in the medium. The recombinant protein has been found to be a member of GH11 family containing two distant glutamic acids as catalytic residues. This report describes yet another new and potent source of xylanase for commercial exploitation by industry in future.


Assuntos
Termitomyces , Escherichia coli/genética , Saccharomyces cerevisiae , Xilosidases
14.
J Ethnopharmacol ; 276: 114147, 2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-33930492

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Some local communities in Cote d'Ivoire use the mushroom Termitomyces schimperi combined with kaolin (TSK) to manage various cancers in patients. However, there is a paucity of data on toxicity, mutagenicity and trace metal constituent of TSK. AIM OF THE STUDY: We sought to investigate the acute and sub-chronic toxicities, mutagenic potential, and trace metal constituents of TSK. MATERIALS AND METHODS: To assess acute toxicity, single doses (1000, 3000 and 5000 mg/kg) of aqueous extract of TSK were administrated per os to Sprague Dawley (SD) rats on Day 1. The rats were then monitored for 13 consecutive days. Sub-chronic toxicity was evaluated by daily administration of 200 and 500 mg/kg of the extract per os for 90 consecutive days. SD rats used as control received distilled water. Signs of toxicity, changes in body weight and mortality were monitored. After the aforementioned monitoring processes, rats were sacrificed and blood collected for full blood count and biochemistry analysis. Animal organs were also collected for histopathological examination. The mutagenic potential of the aqueous extract of TSK (10000 µg/mL) on TA98 Salmonella typhimurium was estimated. Additionally, energy-dispersive X-ray fluorescence (ED-XRF) method was employed to determine trace metal constituents of TSK. RESULTS: Single-dose administration of 5000 mg/kg of TSK did not cause any death in the SD rats; thus, LD50 was above 5000 mg/kg. Administration of 1000 and 3000 mg/kg of the aqueous extract of TSK did not cause any significant change in behaviour and body weight of SD rats during the 14-day monitoring period. However, the mean corpuscular volume and the mean corpuscular haemoglobin concentration increased significantly (p < 0.01) among rats administered 1000 and 3000 mg/kg of TSK. There was a significant increase (p < 0.0001) in alanine transaminase levels in rats administered 1000 and 3000 mg/kg of TSK extract compared with control. Conversely, there was a significant decrease (p=0.0122) in serum creatine level among rats administered 1000 and 3000 mg/kg of TSK extract compared with control. After 14 days, there were minimal changes with isolated organs of TSK-treated and control rats. Furthermore, 90-day treatment with extract of TSK caused no significant change in parameters assessed. TSK induced frameshift gene mutation in S. typhimurium before (p < 0.05) and after metabolic activation (p < 0.001). Elemental analysis of TSK revealed the presence of toxic (aluminium) or potentially toxic (silver, rabidium, titanium and zirconium) elements. CONCLUSIONS: The aqueous extract of TSK showed no toxicity (acute and sub-chronic) at doses tested. These findings are consistent with the absence of heavy metals (i.e., cadmium) and potentially toxic elements (i.e., uranium) in TSK samples analysed. TSK showed some level of mutagenic potential. Further mutagenic and chronic toxicity studies on TSK are required.


Assuntos
Caulim/química , Caulim/toxicidade , Neoplasias/tratamento farmacológico , Extratos Vegetais/química , Extratos Vegetais/toxicidade , Termitomyces/química , Animais , Peso Corporal/efeitos dos fármacos , Côte d'Ivoire , Coração/efeitos dos fármacos , Rim/efeitos dos fármacos , Rim/patologia , Dose Letal Mediana , Fígado/efeitos dos fármacos , Fígado/patologia , Pulmão/efeitos dos fármacos , Pulmão/patologia , Masculino , Medicinas Tradicionais Africanas/métodos , Testes de Mutagenicidade , Miocárdio/patologia , Tamanho do Órgão/efeitos dos fármacos , Ratos Sprague-Dawley , Salmonella typhimurium/efeitos dos fármacos , Baço/efeitos dos fármacos , Baço/patologia , Fatores de Tempo , Testes de Toxicidade Subcrônica , Oligoelementos/análise
15.
Prep Biochem Biotechnol ; 51(5): 488-496, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33063604

RESUMO

Termitomyces sp. OE 147 is one of the active cellulose degraders in the ecosphere and produces large amount of cellobiose dehydrogenase (CDH) and ß-glucosidases when cultivated on cellulose. In order to investigate its effect on cellulose, a highly purified preparation of CDH was obtained from the culture supernatant of the fungus cultivated on cellulose. A combination of ultrafiltration, ion-exchange and gel-filtration chromatography was used to purify CDH by ∼172-fold to a high specific activity of ∼324 U/mg protein on lactose which was used for routine measurement of enzyme activity. The enzyme displayed a pH optimum of 5.0 and stability between pH 5.0 and 8.0 with maximum catalytic efficiency (kcat/Km) of 397 mM-1 s-1 on cellobiose. Incubation of microcrystalline cellulose with the purified CDH led to production of reducing sugars which was accelerated by the addition of FeCl3 during the early stages of incubation. A mass spectrometric analysis revealed fragmentation products of cellulose which were concluded to be cellodextrins, sugars, and corresponding aldonic acids suggesting that CDH can release reducing sugars in the absence of externally added lytic polysaccharide monooxygenases. Polymerized products of glucose were also detected at low intensity.


Assuntos
Desidrogenases de Carboidrato , Celulose/química , Proteínas Fúngicas , Termitomyces/enzimologia , Desidrogenases de Carboidrato/química , Desidrogenases de Carboidrato/isolamento & purificação , Estabilidade Enzimática , Proteínas Fúngicas/química , Proteínas Fúngicas/isolamento & purificação , Especificidade por Substrato , Termitomyces/crescimento & desenvolvimento
16.
Biol Lett ; 16(8): 20200394, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32781906

RESUMO

Although mutualistic symbioses per definition are beneficial for interacting species, conflict may arise if partners reproduce independently. We address how this reproductive conflict is regulated in the obligate mutualistic symbiosis between fungus-growing termites and Termitomyces fungi. Even though the termites and their fungal symbiont disperse independently to establish new colonies, dispersal is correlated in time. The fungal symbiont typically forms mushrooms a few weeks after the colony has produced dispersing alates. It is thought that this timing is due to a trade-off between alate and worker production; alate production reduces resources available for worker production. As workers consume the fungus, reduced numbers of workers will allow mushrooms to 'escape' from the host colony. Here, we test a specific version of this hypothesis: the typical asexual structures found in all species of Termitomyces-nodules-are immature stages of mushrooms that are normally harvested by the termites at a primordial stage. We refute this hypothesis by showing that nodules and mushroom primordia are macro- and microscopically different structures and by showing that in the absence of workers, primordia do, and nodules do not grow out into mushrooms. It remains to be tested whether termite control of primordia formation or of primordia outgrowth mitigates the reproductive conflict.


Assuntos
Isópteros , Termitomyces , Animais , Reprodução , Simbiose
17.
Appl Biochem Biotechnol ; 192(4): 1270-1283, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32720080

RESUMO

Termitomyces fungi associated with fungus-growing termites are the edible mushrooms and can produce useful chemicals, enzymes, and volatile organic compounds (VOCs) that have both fuel and biological potentials. To this purpose, we examined the Termitomyces mycelial growth performance on various substrates, clarified lignocellulose-degrading enzyme activity, and also identified the VOCs produced by Termitomyces. Our results indicated that the optimal nutrition and condition requirements for mycelial growth are D-sorbitol, D-(+)-glucose, and D-(-)-fructose as carbon sources; peptone as well as yeast extract and ammonium tartrate as nitrogen sources; and Mn2+, Na+, and Mg2+ as metal ions with pH range from 7.0 to 8.0. Besides, the orthogonal matrix method results revealed that the ideal composition for mycelial growth is 20 g/L D-(-)-fructose, 5 g/L yeast extract, 0.5 g/L Mg2+, and pH = 7. We also screened various substrates composition for the activity of lignocellulose-degrading enzymes, i.e., lignin peroxidase, manganese peroxidase, ß-glucosidase, a-L-arabinofuranosidase, and laccase. Furthermore, we identified 37 VOCs using GC-MS, and the most striking aspect was the presence of a big series of alcohols and acids, collectively constituted about 49% of the total VOCs. Ergosta-5, 8, 22-trien-3-ol, (3.beta.,22E) was the most plenteous compound constituted 30.369%. This study hopes to establish a better understanding for researchers regarding Termitomyces heimii cultivation on a large scale for the production of lignocellulosic enzymes and some fungal medicine.


Assuntos
Enzimas/metabolismo , Isópteros/microbiologia , Lignina/metabolismo , Termitomyces/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Animais , Enzimas/biossíntese , Concentração de Íons de Hidrogênio , Micélio/crescimento & desenvolvimento , Termitomyces/fisiologia
18.
Chembiochem ; 21(20): 2991-2996, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32470183

RESUMO

Herein, we report the targeted isolation and characterization of four linear nonribosomally synthesized tetrapeptides (pseudoxylaramide A-D) and two cyclic nonribosomal peptide synthetase-polyketide synthase-derived natural products (xylacremolide A and B) from the termite-associated stowaway fungus Pseudoxylaria sp. X187. The fungal strain was prioritized for further metabolic analysis based on its taxonomical position and morphological and bioassay data. Metabolic data were dereplicated based on high-resolution tandem mass spectrometry data and global molecular networking analysis. The structure of all six new natural products was elucidated based on a combination of 1D and 2D NMR analysis, Marfey's analysis and X-ray crystallography.


Assuntos
Produtos Biológicos/química , Descoberta de Drogas , Oligopeptídeos/química , Peptídeos Cíclicos/química , Policetídeos/química , Termitomyces/química , Produtos Biológicos/isolamento & purificação , Cristalografia por Raios X , Modelos Moleculares , Conformação Molecular , Ressonância Magnética Nuclear Biomolecular , Oligopeptídeos/isolamento & purificação , Peptídeos Cíclicos/isolamento & purificação , Policetídeos/isolamento & purificação , Estereoisomerismo
19.
J Ethnobiol Ethnomed ; 16(1): 11, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32131860

RESUMO

BACKGROUND: Menge District has long been inhabited by people who have a long tradition of using wild mushrooms mainly as food, source of income, and medicine. Extensive utilization of wild edible mushrooms (WEM) coupled with an ever-increasing population growth, deforestation, and agricultural land expansion threatens fungal diversity and WEM in the area. Hence, this study is aimed at documenting and analyzing the ethnomycological knowledge of the people in order to preserve the dwindling WEM wealth and associated indigenous knowledge. METHODS: Ethnomycological data were collected using semi-structured interviews, focus group discussions, participant observations, and walk-in-the-woods methods. Statistical tests were used to compare the indigenous knowledge and practice of wild mushroom among different informant categories using One-way ANOVA and t tests. RESULTS: A total of 20 ethnomycologically important wild mushroom species belonging to ten genera and six families were identified, of which 15 were reported to be edible in the District. The family Lyophyllaceae was represented by the highest number of species (nine species, 45%) followed by Agaricaceae (seven species, 35%) and each of the remaining four families had single species representation. Significant difference (P < 0.05) was observed on the mean number of WEM reported among different group of respondents. Wild edible mushroom collection habit and practice was significantly (P < 0.05) influenced by gender, age, and literacy level. The output of preference ranking exercise indicated Termitomyces schimperi was ranked first followed by Termitomyces letestui, Termitomyces microcarpus, and Termitomyces eurhizusas as the most preferred edible mushrooms respectively. CONCLUSION: The present study shows that Menge District is rich in wild mushroom diversity and associated indigenous knowledge. However, anthropogenic factors together with loss of indigenous knowledge and very poor conservation efforts threaten the survival of economically and ecologically important mushrooms in the area. Thus, complementary in situ and ex situ mushroom conservation strategy is highly recommended.


Assuntos
Agaricales/classificação , Conhecimento , Medicina Tradicional , Adolescente , Adulto , Etiópia , Feminino , Alimentos , Humanos , Masculino , Pessoa de Meia-Idade , Termitomyces , Adulto Jovem
20.
Int J Biol Macromol ; 151: 305-311, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32084474

RESUMO

A water soluble heteroglycan (THPS) of an average molecular weight ~1.98 × 105 Da was isolated from the aqueous extract of the fruit bodies of an edible mushroom Termitomyces heimii. Structural characterization of THPS was carried out using acid hydrolysis, methylation analysis, periodate oxidation, Smith degradation and 1D/2D NMR studies. Sugar analysis indicated the presence of glucose, mannose, galactose, and fucose in a molar ratio of nearly 6:2:2:1. The repeating unit of the THPS had a backbone consisting of four (1 â†’ 3)-ß-d-glucopyranosyl, one (1 â†’ 6)-ß-d-glucopyranosyl, two (1 â†’ 3)-α-D-manopyranosyl, and two (1 â†’ 6)-α-D-galactopyranosyl residues, out of which one (1 â†’ 3)-ß-d-glucopyranosyl residue was branched at O-6 position with terminal ß-d-glucopyranosyl residue and one (1 â†’ 6)-α-D-galactopyranosyl residue was branched at O-2 position with terminal α-L-fucopyranosyl residue.


Assuntos
Agaricales/química , Polissacarídeos/química , Termitomyces/química , Cromatografia Líquida , Estrutura Molecular , Polissacarídeos/isolamento & purificação , Análise Espectral , Espectrometria de Massas em Tandem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...