RESUMEN

Peritoneal dialysis (PD)-associated fungal peritonitis, although rare, presents significant challenges in diagnosis and management. Here, we present the first case of PD-related peritonitis attributed to Psathyrella candolleana and highlight a potential route of infection through contamination from the PD catheter belt. A 37-year-old female, with a history of heart and lung transplantation and undergoing continuous ambulatory PD, presented with acute abdominal pain and cloudy PD effluent (PDE). Genetic analysis of PDE and PD catheter tip confirmed diagnosis of P. candolleana. Treatment was successful without any relapses with timely PD catheter removal and an extended course of antifungal therapy. The root cause analysis suspected the dirt-stained PD catheter belt as the origin of contamination. In conclusion, this is the first case of P. candolleana infection in PD-related peritonitis. Preventive strategies should prioritize hygiene practices, including the PD belt to mitigate the risk of contamination and subsequent infections of such pathogens.

RESUMEN

BACKGROUND: Laccases can oxidize a broad spectrum of substrates, offering promising applications in various sectors, such as bioremediation, biomass fractionation in future biorefineries, and synthesis of biochemicals and biopolymers. However, laccase discovery and optimization with a desirable pH optimum remains a challenge due to the labor-intensive and time-consuming nature of the traditional laboratory methods. RESULTS: This study presents a machine learning (ML)-integrated approach for predicting pH optima of basidiomycete fungal laccases, utilizing a small, curated dataset against a vast metagenomic data. Comparative computational analyses unveiled the structural and pH-dependent solubility differences between acidic and neutral-alkaline laccases, helping us understand the molecular bases of enzyme pH optimum. The pH profiling of the two ML-predicted alkaline laccase candidates from the basidiomycete fungus Lepista nuda further validated our computational approach, showing the accuracy of this comprehensive method. CONCLUSIONS: This study uncovers the efficacy of ML in the prediction of enzyme pH optimum from minimal datasets, marking a significant step towards harnessing computational tools for systematic screening of enzymes for biotechnology applications.

RESUMEN

We report an annotated draft genome of Heterobasidion occidentale, a fungus (Basidiomycota, Agaricomycetes) that has pathogenic and saprophytic lifestyles. This fungus belongs to the H. annosum (Fr.) Bref. sensu lato species complex that comprises several root rot pathogens. Heterobasidion occidentale causes annosus root and butt rot primarily in true fir (Abies spp.) and spruce (Picea spp.) species throughout western North America.

RESUMEN

Polyethylene, one of the most used petroleum-derived polymers, causes serious environmental pollution. The ability of Pleurotus ostreatus to degrade UV-treated and untreated recycled and unused (new) low-density polyethylene (LDPE) films was studied. We determined the fungal biomass production, enzyme production, and enzyme yield. Changes in the chemical structure and surface morphology of the LDPE after fungal growth were analyzed using FTIR spectroscopy and SEM. Functional group indices and contact angles were also evaluated. In general, the highest Lac (6013 U/L), LiP (2432 U/L), MnP (995 U/L) and UP (6671 U/L) activities were observed in irradiated recycled LDPE (IrRPE). The contact angle of all samples was negatively correlated with fermentation time; the smaller the contact angle, the longer the fermentation time, indicating effective biodegradation. The IrRPE samples exhibited the smallest contact angle (49°) at 4 weeks, and the samples were fragmented (into two pieces) at 5 weeks. This fungus could degrade unused (new) LDPE significantly within 6 weeks. The biodegradation of LDPE proceeded faster in recycled than in unused samples, which can be enhanced by exposing LDPE to UV radiation. Enzymatic production during fungal growth suggest that LDPE degradation is initiated by laccase (Lac) followed by lignin peroxidase (LiP), whereas manganese peroxidase (MnP) and unspecific peroxygenase (UP) are involved in the final degradation process. This is the first experimental study on the fungal growth and its main enzymes involved in LDPE biodegradation. This fungus has great promise as a safe, efficient, and environmentally friendly organism capable of degrading LDPE.

Asunto(s)

Biodegradación Ambiental , Lacasa , Pleurotus , Polietileno , Rayos Ultravioleta , Pleurotus/crecimiento & desarrollo , Pleurotus/metabolismo , Polietileno/química , Polietileno/metabolismo , Lacasa/metabolismo , Fermentación , Reciclaje , Biomasa , Peroxidasas/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier

RESUMEN

Phellinus caribaeo-quercicola is a basidiomycetous fungus, isolated as an endophyte in this study from the healthy and symptomless leaves of Inula racemosa Hook. f., an important medicinal herb growing in Kashmir Himalaya. This study combines morphological, molecular and phylogenetic techniques to identify the fungal endophyte, using the ITS sequence of nrDNA. A detached leaf assay was conducted to assess the pathogenicity of the fungal endophyte suggesting its mutually symbiotic relationship with the host. The authors also investigated the antifungal potential of the isolated endophytic strain to ascertain its use as a biocontrol agent. The study shows that P. caribaeo-quercicola INL3-2 strain exhibits biocontrol activity against four key fungal phytopathogens that cause significant agronomic and economic losses: Aspergillus flavus, Aspergillus niger, Fusarium solani, and Fusarium oxysporum. Notably, P. caribaeo-quercicola INL3-2 strain is highly effective against A. flavus, with an inhibition percentage of 57.63%. In addition, this study investigates the antioxidant activity of P. caribaeo-quercicola INL3-2 strain crude extracts using ethyl acetate and methanol as solvents. The results showed that the methanolic fraction of P. caribaeo-quercicola exhibits potential as an antioxidant agent, with an IC50 value of 171.90 ± 1.15 µg/mL. This investigation is first of its kind and marks the initial report of this fungal basidiomycete, P. caribaeo-quercicola, as an endophyte associated with a medicinal plant. The findings of this study highlight the potential of P. caribaeo-quercicola INL3-2 strain as a dual-action agent with both biocontrol and antioxidant properties consistent with the medicinal properties of Inula racemosa. This endophytic fungus could be a promising source of natural compounds for use in agriculture, medicine, and beyond.

Asunto(s)

Antifúngicos , Antioxidantes , Basidiomycota , Endófitos , Filogenia , Hojas de la Planta , Endófitos/aislamiento & purificación , Endófitos/metabolismo , Endófitos/fisiología , Endófitos/genética , Antioxidantes/farmacología , Antioxidantes/metabolismo , Basidiomycota/efectos de los fármacos , Hojas de la Planta/microbiología , Antifúngicos/farmacología , Antifúngicos/metabolismo , Fusarium/efectos de los fármacos , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Agentes de Control Biológico/farmacología , Aspergillus/metabolismo , Aspergillus/efectos de los fármacos , India , Aspergillus flavus/efectos de los fármacos , Aspergillus flavus/metabolismo , Aspergillus flavus/crecimiento & desarrollo , ADN de Hongos/genética , Simbiosis

RESUMEN

Chitin is an essential structural component of fungal cell walls composed of transmembrane proteins called chitin synthases (CHSs), which have a large range of reported effects in ascomycetes; however, are poorly understood in agaricomycetes. In this study, evolutionary and molecular genetic analyses of chs genes were conducted using genomic information from nine ascomycete and six basidiomycete species. The results support the existence of seven previously classified chs clades and the discovery of three novel basidiomycete-specific clades (BI-BIII). The agaricomycete fungus Pleurotus ostreatus was observed to have nine putative chs genes, four of which were basidiomycete-specific. Three of these basidiomycete specific genes were disrupted in the P. ostreatus 20b strain (ku80 disruptant) through homologous recombination and transformants were obtained (Δchsb2, Δchsb3, and Δchsb4). Despite numerous transformations Δchsb1 was unobtainable, suggesting disruption of this gene causes a crucial negative effect in P. ostreatus. Disruption of these chsb2-4 genes caused sparser mycelia with rougher surfaces and shorter aerial hyphae. They also caused increased sensitivity to cell wall and membrane stress, thinner cell walls, and overexpression of other chitin and glucan synthases. These genes have distinct roles in the structural formation of aerial hyphae and cell walls, which are important for understanding basidiomycete evolution in filamentous fungi.

Asunto(s)

Quitina Sintasa , Quitina , Proteínas Fúngicas , Filogenia , Pleurotus , Quitina Sintasa/genética , Pleurotus/genética , Pleurotus/enzimología , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Quitina/metabolismo , Pared Celular/genética , Pared Celular/metabolismo , Evolución Molecular , Basidiomycota/genética , Basidiomycota/enzimología

RESUMEN

Laccase isoforms from basidiomycetes exhibit a superior redox potential compared to commercially available laccases obtained from ascomycete fungi, rendering them more reactive toward mono-substituted phenols and polyphenolic compounds. However, basidiomycetes present limitations for large-scale culture in liquid media, restraining the current availability of laccases from this fungal class. To advance laccase production from basidiomycetes, a newly designed 14-L low-shear aerated and agitated bioreactor provided enzyme titers up to 23.5 IU/mL from Trametes versicolor cultures. Produced enzymes underwent ultrafiltration and LC/MS-MS characterization, revealing the predominant production of only two out of the ten laccases predicted in the T. versicolor genome. Process simulation and economic analysis using SuperPro designer® suggested that T. versicolor laccase could be produced at US$ 3.60/kIU in a 200-L/batch enterprise with attractive economic parameters and a payback period of 1.7 years. The study indicates that new bioreactors with plain design help to produce low-cost enzymes from basidiomycetes.

Asunto(s)

Reactores Biológicos , Lacasa , Lacasa/metabolismo , Lacasa/biosíntesis , Trametes/enzimología , Polyporaceae

RESUMEN

A sporeless strain is an important breeding target in the mushroom industry. However, basidiospore production in the oyster mushroom Pleurotus ostreatus has been shown to be impaired by single-gene mutations in only two meiosis-related genes, mer3 and msh4. This study proposed a strategy for identifying the genes essential for basidiospore formation after meiotic division to determine new targets for molecular breeding. RNA-seq analysis was performed to identify P. ostreatus genes that are specifically expressed in the gill tissue of fruiting bodies, where basidiospore formation occurs. Transcriptome data during fruiting development of Coprinopsis cinerea, in which the meiotic steps progress synchronously, were then used to identify genes that are active in the postmeiotic stages. Based on these comparative analyses, five P. ostreatus genes were identified. Plasmids containing expression cassettes for hygromycin B-resistance screening, Cas9, and single-guide RNA targeting each gene were introduced into the protoplasts of dikaryotic strain, PC9×#64, to generate dikaryotic gene disruptants. Among the obtained transformants, three dikaryotic pcl1 disruptants and two cro6c disruptants did not produce basidiospores. Microscopic analyses indicated that spore formation was arrested at particular stages in these gene disruptants. These results indicate that these two genes are essential for mature spore formation in this fungus.

Asunto(s)

Cuerpos Fructíferos de los Hongos , Meiosis , Pleurotus , Esporas Fúngicas , Pleurotus/genética , Pleurotus/crecimiento & desarrollo , Esporas Fúngicas/genética , Esporas Fúngicas/crecimiento & desarrollo , Meiosis/genética , Cuerpos Fructíferos de los Hongos/genética , Cuerpos Fructíferos de los Hongos/crecimiento & desarrollo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulación Fúngica de la Expresión Génica/genética , Genes Fúngicos/genética , Genes Esenciales/genética , Transcriptoma/genética

RESUMEN

Hormographiella aspergillata is a basidiomycete exceptionally involved in invasive fungal infections (IFI). We report a case of H. aspergillata pulmonary infection in a 30-year-old female in a context of pancytopenia and relapsed of acute myeloid leukemia (AML). She presented with fever, thoracic pain, left pleural effusion and pneumonia, diagnosed on chest X-ray and CT-scan. Direct examination of a bronchoalveolar lavage (BAL) specimen performed on day (d) 10 was negative, while the culture was positive on d30. H. aspergillata was suspected, considering macroscopic and microscopic examination. Its identification was confirmed using Microflex® Bruker mass spectrometry and pan-fungal (PF)-PCR assay followed by DNA sequencing. After this initial diagnosis, the patient was monitored for 2.8 years. She was treated with liposomal amphotericin B and/or voriconazole until switching to isavuconazole on d298 due to side-effects. This antifungal treatment was maintained until d717 and then discontinued, the patient being considered as cured. Over this follow-up period, the patient was submitted to recurrent pulmonary sampling. Each time, cultures were negative, while PF - PCR assays and DNA sequencing confirmed the presence of H. aspergillata. The present case-report is the 32nd observation of H. aspergillata invasive infection showing that this IFI is still infrequent. Fifteen have occurred in patients with AML, which appears as the most frequent underlying disease favoring this IFI. Six recent case-reports in addition to ours highlight PF-PCR assays and DNA sequencing as relevant diagnostic tools that must be included in routine diagnosis and monitoring of IFI, specifically those due to rare basidiomycetes.

Asunto(s)

Agaricales , Basidiomycota , Leucemia Mieloide Aguda , Enfermedades Pulmonares Fúngicas , Neumonía , Adulto , Femenino , Humanos , Antifúngicos/uso terapéutico , Basidiomycota/genética , Leucemia Mieloide Aguda/tratamiento farmacológico , Enfermedades Pulmonares Fúngicas/diagnóstico , Enfermedades Pulmonares Fúngicas/tratamiento farmacológico , Enfermedades Pulmonares Fúngicas/microbiología , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN

RESUMEN

This paper aims to develop and assess the in vitro effects on ruminal fermentation and greenhouse gas parameters of new bioproducts for beef cattle diets, carried out by solid-state fermentation of peach palm shells colonized by Lentinula edodes (SSF) and after Shiitake mushroom cultivation in axenic blocks (SMS). In vitro experiments were performed to assess the in vitro gas production, digestibility, and fiber degradation of formulated total diets. Bioproducts presented high ß-glucans (9.44---11.27 %) and protein (10.04---8.35 %) contents, as well as similar digestibility to conventional diets. SMS diet had the lowest methane and carbon dioxide (19.1 and 84.1 mM/g OM) production, and the SSF diet presented lower carbon dioxide production (98.9 mM/g OM) than other diets, whereas methane was similar. This study highlighted a sustainable use of byproducts for beef cattle diets, promising for digestibility, nutritional value, ß-glucans incorporation, and environmental impact mitigation, favoring the circular bioeconomy.

Asunto(s)

Arecaceae , Hongos Shiitake , beta-Glucanos , Animales , Bovinos , Hongos Shiitake/metabolismo , Alimentación Animal/análisis , Dióxido de Carbono/metabolismo , Digestión , Arecaceae/metabolismo , Dieta/veterinaria , Fermentación , Metano/metabolismo , Rumen/metabolismo

RESUMEN

BACKGROUND: Ganoderma boninense is a phytopathogen of oil palm, causing basal and upper stem rot diseases. METHODS: The genome sequence was used as a reference to study gene expression during growth in a starved carbon (C) and nitrogen (N) environment with minimal sugar and sawdust as initial energy sources. This study was conducted to mimic possible limitations of the C-N nutrient sources during the growth of G. boninense in oil palm plantations. RESULTS: Genome sequencing of an isolate collected from a palm tree in West Malaysia generated an assembly of 67.12 Mb encoding 19,851 predicted genes. Transcriptomic analysis from a time course experiment during growth in this starvation media identified differentially expressed genes (DEGs) that were found to be associated with 29 metabolic pathways. During the active growth phase, 26 DEGs were related to four pathways, including secondary metabolite biosynthesis, carbohydrate metabolism, glycan metabolism and mycotoxin biosynthesis. G. boninense genes involved in the carbohydrate metabolism pathway that contribute to the degradation of plant cell walls were up-regulated. Interestingly, several genes associated with the mycotoxin biosynthesis pathway were identified as playing a possible role in pathogen-host interaction. In addition, metabolomics analysis revealed six metabolites, maltose, xylobiose, glucooligosaccharide, glycylproline, dimethylfumaric acid and arabitol that were up-regulated on Day2 of the time course experiment. CONCLUSIONS: This study provides information on genes expressed by G. boninense in metabolic pathways that may play a role in the initial infection of the host.

Asunto(s)

Arecaceae , Ganoderma , Micotoxinas , Arecaceae/genética , Arecaceae/metabolismo , Enfermedades de las Plantas/genética , Perfilación de la Expresión Génica , Ganoderma/genética , Micotoxinas/metabolismo

RESUMEN

A comprehensive analysis to survey heme-binding proteins produced by the white-rot fungus Phanerochaete chrysosporium was achieved using a biotinylated heme-streptavidin beads system. Mitochondrial citrate synthase (PcCS), glyceraldehyde 3-phosphate dehydrogenase (PcGAPDH), and 2-Cys thioredoxin peroxidase (mammalian HBP23 homolog) were identified as putative heme-binding proteins. Among these, PcCS and PcGAPDH were further characterized using heterologously expressed recombinant proteins. Difference spectra of PcCS titrated with hemin exhibited an increase in the Soret absorbance at 414 nm, suggesting that the axial ligand of the heme is a His residue. The activity of PcCS was strongly inhibited by hemin with Ki oxaloacetate of 8.7 µM and Ki acetyl-CoA of 5.8 µM. Since the final step of heme biosynthesis occurred at the mitochondrial inner membrane, the inhibition of PcCS by heme is thought to be a physiological event. The inhibitory mode of the heme was similar to that of CoA analogues, suggesting that heme binds to PcCS at His347 at the AcCoA-CoA binding site, which was supported by the homology model of PcCS. PcGAPDH was also inhibited by heme, with a lower concentration than that for PcCS. This might be caused by the different location of these enzymes. From the integration of these phenomena, it was concluded that metabolic regulations by heme in the central metabolic and heme synthetic pathways occurred in the mitochondria and cytosol. This novel pathway crosstalk between the central metabolic and heme biosynthetic pathways, via a heme molecule, is important in regulating the metabolic balance (heme synthesis, ATP synthesis, flux balance of the tricarboxylic acid (TCA) cycle and cellular redox balance (NADPH production) during fungal aromatic degradation. KEY POINTS: • A comprehensive survey of heme-binding proteins in P. chrysosporium was achieved. • Several heme-binding proteins including CS and GAPDH were identified. • A novel metabolic regulation by heme in the central metabolic pathways was found.

Asunto(s)

Vías Biosintéticas , Phanerochaete , Animales , Hemo , Phanerochaete/genética , Hemina , Proteínas de Unión al Hemo , Mamíferos

RESUMEN

Laccase is a superfamily of ligninolytic enzymes known to degrade a wide variety of xenobiotics, including synthetic dyes. Congo Red (CR) has a diazo dye function, carcinogenic and mutagenic potential, and is currently applied in clinical analysis. The objective of this work was to produce and characterize the crude extract of Lentinus sp. in semi-solid fermentation (FSS) and perform in vitro and in silico studies to assess the potential of the crude extract to discolor the CR dye. Laccase activity was determined using ABTS as substrate and characterized. The in vitro discoloration was carried out using experimental design 22 at room temperature and monitored at 340 nm for 24h. Molecular docking and molecular dynamics simulations were performed between laccase and CR. The maximum laccase activity production was 29.63 U L-1 with six days of FSS. The optimal temperature and pH were 50 °C and 3.0, respectively. Discoloration of the CR dye was obtained only in tests containing CuSO4. Laccase formed stable complexes with the dye, presenting negative binding energy values ranging from -70.94 to -63.16 kcal mol-1 and the occurrence of seven hydrogen bonds. Molecular dynamics results showed the stability of the system (RMSD ranging from 1.0 to 2.5 Ä) and protein-ligand interaction along simulation. RMSF values pointed residues at the end of chains A (residues 300 to 305, 480 to 500) and B (residues 650 to 655 and 950 to 1000) as the most flexible regions of the laccase. This study highlighted the enzymatic action in the bioremediation of CR in vitro in agreement with the in silico simulations that demonstrate the enzyme potential.Communicated by Ramaswamy H. Sarma.

Asunto(s)

Rojo Congo , Lentinula , Rojo Congo/química , Colorantes/química , Lacasa/química , Lacasa/metabolismo , Simulación del Acoplamiento Molecular , Lentinula/metabolismo , Proyectos de Investigación , Mezclas Complejas

RESUMEN

Multicopper oxidases (MCOs) share a common catalytic mechanism of activation by oxygen and cupredoxin-like folding, along with some common structural determinants. Laccases constitute the largest group of MCOs, with fungal laccases having the greatest biotechnological applicability due to their superior ability to oxidize a wide range of aromatic compounds and lignin, which is enhanced in the presence of redox mediators. The adaptation of these versatile enzymes to specific application processes can be achieved through the directed evolution of the recombinant enzymes. On the other hand, their substrate versatility and the low sequence homology among laccases make their exact classification difficult. Many of the ever-increasing amounts of MCO entries from fungal genomes are automatically (and often wrongly) annotated as laccases. In a recent comparative genomic study of 52 basidiomycete fungi, MCO classification was revised based on their phylogeny. The enzymes clustered according to common structural motifs and theoretical activities, revealing three novel groups of laccase-like enzymes. This review provides an overview of the structure, catalytic activity, and oxidative mechanism of fungal laccases and how their biotechnological potential as biocatalysts in industry can be greatly enhanced by protein engineering. Finally, recent information on newly identified MCOs with laccase-like activity is included.

Asunto(s)

Basidiomycota , Lacasa , Lacasa/metabolismo , Basidiomycota/metabolismo , Oxidación-Reducción , Ingeniería de Proteínas

RESUMEN

Spinning disc confocal microscopical research was conducted on living mating hyphae of the tetrapolar basidiomycete Schizophyllum commune. Haploid strains with either the same or different A and B mating-type genes and expressing differently labelled histone 2B were confronted. In the haploid hyphae histone 2B mCherry and histone 2B EGFP were visualized as red and green nuclei, respectively. In hyphae with the same A but different B genes, the red and green nuclei were observed next to each other. This indicated that nuclear migration between strains, regulated by the B mating type, had taken place. The compatible mating with different A and B genes produced a high number of mixed EFGP/mCherry, yellow nuclei. The mixed nuclei resulted from nearby divisions of nuclei encoding different histones and mating-type genes. During this process, the histones with the different labels were incorporated in the same nuclei, along with the heterodimerized transcription factors encoded by the different A mating-type genes and present around the nuclei. This led to the activation of the A-regulated pathway and indicated that different A genes are important to the cell cycle activation of a compatible mating. Consequently, a yellow nuclear pair stuck together, divided synchronously and proceeded in the migration hyphae towards the colony periphery, where the dikaryotization was promoted by branch formation from the migration hyphae.

RESUMEN

Chanterelles are one of the most highly valued wild edible mushroom genera worldwide. This work aimed to investigate the nutritional characteristics and volatile compounds' profile of Cantharellus alborufescens for the first time. Proximate analysis was performed according to the Association of Official Agricultural Chemists, while the mineral contents and the volatile compounds were determined using ICP-MS and GC-MS, respectively. C. alborufescens had an average of 25.8% protein, 5.5% fat, 12.7% ash, and 55.9% carbohydrates, including 11.4% fiber per dw of mushroom. Further analyses of the fat and protein contents revealed high amounts of polyunsaturated fatty acids as well as monosodium glutamate-like amino acids. Linoleic acid (42.0% of fat) and oleic acid (28.6% of fat) were the major fatty acids, while leucine (1.2%) and lysine (0.9%) were the most abundant essential amino acids. The results showed that C. alborufescens contained 3.1 µg/g vitamin D2 and 4.9 mg/g vitamin E per dw, as well as notable quantities of macro- and microelements, such as potassium, calcium, magnesium, and iron. GC-MS analysis revealed various volatile compounds such as acetaldehyde, n-hexanal, 3-methylbutanal, 1-octen-3-ol, etc. In conclusion, this study supports the use of C. alborufescens as a food rich in fiber and vitamin E, with a suitable amount of protein and other nutrients.

Asunto(s)

Agaricales , Agaricales/química , Odorantes/análisis , Ácidos Grasos , Vitamina E

RESUMEN

Sesquiterpenes are a type of abundant natural product with widespread applications in several industries. They are biosynthesized by sesquiterpene synthases (STSs). As valuable and abundant biological resources, mushroom-forming fungi are rich in new sesquiterpenes and STSs, which remain largely unexploited. In the present study, we collected information on 172 STSs from mushroom-forming fungi with experimentally characterized products from the literature and sorted them to develop a dataset. Furthermore, we analyzed and discussed the phylogenetic tree, catalytic products, and conserved motifs of STSs. Phylogenetic analysis revealed that the STSs were clustered into four clades. Furthermore, their cyclization reaction mechanism was divided into four corresponding categories. This database was used to predict 12 putative STS genes from the edible fungi Flammulina velutipes. Finally, three FvSTSs were selected to experimentally characterize their functions. FvSTS03 predominantly produced Δ-cadinol and FvSTS08 synthesized ß-barbatene as the main product; these findings were consistent with those of the functional prediction analysis. A product titer of 78.8 mg/L ß-barbatene was achieved in Saccharomyces cerevisiae via metabolic engineering. Our study findings will help screen or design STSs from fungi with specific product profiles as functional elements for applications in synthetic biology.

RESUMEN

The exploration of the western forests of Algeria led to the remarkable discovery of the first occurrence of Lepista sordida, an edible wild mushroom of significant culinary importance for the local community, traditionally consumed in its natural state. This discovery was made possible through the use of various methods, including macroscopic observations (revealing a violet color) as well as microscopic observations conducted using scanning electron microscopy (SEM), revealing a cylindrical shape with distinct contours. Additionally, molecular analyses were conducted. Genomic DNA was extracted from the mycelium, followed by DNA amplification using specific primers targeting the internal transcribed spacer region (ITS1 and ITS2). After PCR reactions and sequencing of the obtained amplicons, the nucleotide sequences of the mycelium were submitted to the GenBank database of NCBI with the assigned accession number: MZ928450.1. These sequences were subsequently used to construct the phylogenetic tree. Furthermore, an in-depth study of physicochemical parameters was undertaken to determine the optimal conditions for cultivating the mycelium of this edible wild mushroom, including pH, temperature, relative humidity, and light. Different temperatures were examined: 20, 25, 30, 35, 40, and 45 °C. The effect of pH on mycelium growth was studied using a PDA agar medium with buffered values of 4, 5, 5.6, 6, 7, and 8. Similarly, six levels of relative humidity were tested: 14, 50, 74, 80, 95, and 100%. A study on the impact of light on mycelium growth was conducted by exposing Petri dishes inoculated with PDA to a light intensity of 500 lux for 5, 10, 15, 20, and 24 h. The results clearly demonstrated that variations in these different physicochemical parameters significantly influenced mycelium growth. For the Lepista sordida strain, growth was favored at pH levels of 4, 5, 6, and 6, with no growth observed at pH 7 and 8. The optimal temperature range for mycelium growth of Lepista sordida was 20-25 °C, while no growth was observed at 30, 35, 40, and 45 °C. Relative humidity levels of 74, 80, and 95% showed no significant differences. Optimization of mycelium growth and primordia production in Lepista sordida were successfully achieved. Optimal conditions for the primordia phase were identified as 25 °C, with humidity ranging from 90 to 95%. A nutritional analysis of fresh sporophores was conducted using established analytical methods. Notably, the nutritional composition of Lepista sordida sporophores exhibited high significance for the following parameters: moisture content (67.23 ± 1.90%), ash content (9.35 ± 0.66%), fat content (3.25 ± 0.24%), protein content (17.22 ± 0.38%), and carbohydrate content (63.83 ± 1.23%).

RESUMEN

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.

Asunto(s)

Isópteros , Termitomyces , Animales , Isópteros/genética , Isópteros/microbiología , Termitomyces/genética , Hongos/genética , Genómica , Simbiosis/genética , Ligamiento Genético

RESUMEN

During a survey of floricolous yeasts in Portugal, a basidiomycetous yeast representing a novel species in the genus Hannaella was isolated in Portugal from the flower of Lantana camara, an ornamental exotic species native to Central and South America. A combination of phylogenetic analyses of DNA barcode sequences used in yeast molecular systematics, namely the D1/D2 domain and the complete internal transcribed spacer (ITS) region supported the recognition of a new species of Hannaella, that we designate Hannaella floricola sp. nov. (ex-type strain PYCC 9191T=CBS 18097T). Although the assignment of the new species to the genus Hannaella was evident, the detection of its closest relatives appeared more problematic. Nevertheless, our analyses suggested that H. floricola sp. nov. belongs a clade that also includes H. coprosmae, H. oryzae and H. surugaensis, together four candidate novel species. In addition we provide the molecular identification of several unidentified strains whose D1/D2 and ITS sequences are available from GenBank.

Asunto(s)

Ascomicetos , Basidiomycota , Lantana , ADN de Hongos/genética , Lantana/genética , Filogenia , Portugal , ADN Espaciador Ribosómico/genética , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Técnicas de Tipificación Micológica , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Composición de Base , Ácidos Grasos/química , Ascomicetos/genética , Flores