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Proceedings of the National Academy of... Mar 2008The full-genome sequencing of the filamentous fungi Aspergillus nidulans, Aspergillus niger, and Aspergillus oryzae has opened possibilities for studying the cellular... (Comparative Study)
Comparative Study
The full-genome sequencing of the filamentous fungi Aspergillus nidulans, Aspergillus niger, and Aspergillus oryzae has opened possibilities for studying the cellular physiology of these fungi on a systemic level. As a tool to explore this, we are making available an Affymetrix GeneChip developed for transcriptome analysis of any of the three above-mentioned aspergilli. Transcriptome analysis of triplicate batch cultivations of all three aspergilli on glucose and xylose media was used to validate the performance of the microarray. Gene comparisons of all three species and cross-analysis with the expression data identified 23 genes to be a conserved response across Aspergillus sp., including the xylose transcriptional activator XlnR. A promoter analysis of the up-regulated genes in all three species indicates the conserved XlnR-binding site to be 5'-GGNTAAA-3'. The composition of the conserved gene-set suggests that xylose acts as a molecule, indicating the presence of complex carbohydrates such as hemicellulose, and triggers an array of degrading enzymes. With this case example, we present a validated tool for transcriptome analysis of three Aspergillus species and a methodology for conducting cross-species evolutionary studies within a genus using comparative transcriptomics.
Topics: Aspergillus; Down-Regulation; Fungal Proteins; Gene Expression Profiling; Gene Expression Regulation, Fungal; Oligonucleotide Array Sequence Analysis; Trans-Activators; Up-Regulation
PubMed: 18332432
DOI: 10.1073/pnas.0709964105 -
Biotechnology Letters Jan 2021Evaluation of morphology and secondary metabolites production in Aspergillus terreus ATCC 20542 cultures over a wide range of lactose and yeast extract concentrations...
Exploring the extremes: applying high concentration of yeast extract leads to drastic morphological changes and elimination of (+)-geodin and asterric acid production in Aspergillus terreus submerged cultures.
OBJECTIVE
Evaluation of morphology and secondary metabolites production in Aspergillus terreus ATCC 20542 cultures over a wide range of lactose and yeast extract concentrations from 0.2 up to an extremely high level of 200 g l.
RESULTS
The morphological differences of mycelial objects were quantified with the use of morphological parameters calculated by applying the tools of digital image analysis. At 200 g l of yeast extract clumps and loose hyphae were recorded instead of pellets commonly observed in submerged cultures of A. terreus. Under these conditions the biosynthesis of (+)-geodin and asterric acid was totally blocked, lovastatin formation was found to be at a relatively low level and biomass production turned out to be greater than in the remaining variants, where the pelleted growth was observed. At 200 g l of lactose the production of lovastatin, (+)-geodin and asterric acid was visibly stimulated compared to the media containing 0.2, 2 and 20 g l of the sugar substrate, but at the same time no traces of butyrolactone I could be detected in the broth. Lactose at the extremely high concentration of 200 g l did not induce the drastic morphological changes observed in the case of 200 g l of yeast extract. It was proved that at the C/N values as low as 4 and as high as 374 A. terreus not only continued to display growth but also exhibited the production of secondary metabolites. The use of cultivation media representing the equivalent C/N ratios led to different metabolic and morphological outcomes depending on the concentration of lactose and yeast extract that contributed to the given C/N value.
CONCLUSION
The extremely high concentration of yeast extract leads to marked morphological changes of A. terreus and the elimination of (+)-geodin and asterric production, while applying the excess of lactose is stimulatory in terms of lovastatin production.
Topics: Aspergillus; Benzofurans; Biological Products; Mycelium; Phenyl Ethers; Saccharomyces cerevisiae
PubMed: 33026584
DOI: 10.1007/s10529-020-03018-5 -
Brazilian Journal of Microbiology :... Jun 2020In recent years, the intensification of the use of immunosuppressive therapies has increased the incidence of invasive infections caused by opportunistic fungi.... (Review)
Review
In recent years, the intensification of the use of immunosuppressive therapies has increased the incidence of invasive infections caused by opportunistic fungi. Considering that, the spread of azole resistance and amphotericin B (AmB) inefficiency against some clinical and environmental isolates has been described. Thus, to avoid a global problem when controlling fungal infections and critical failures in medicine, and food security, new approaches for drug target identification and for the development of new treatments that are more effective against pathogenic fungi are desired. Recent studies indicate that protein acetylation is present in hundreds of proteins of different cellular compartments and is involved in several biological processes, i.e., metabolism, translation, gene expression regulation, and oxidative stress response, from prokaryotes and eukaryotes, including fungi, demonstrating that lysine acetylation plays an important role in essential mechanisms. Lysine acetyltransferases (KATs) and lysine deacetylases (KDACs), the two enzyme families responsible for regulating protein acetylation levels, have been explored as drug targets for the treatment of several human diseases and infections. Aspergilli have on average 8 KAT genes and 11 KDAC genes in their genomes. This review aims to summarize the available knowledge about Aspergillus spp. azole resistance mechanisms and the role of lysine acetylation in the control of biological processes in fungi. We also want to discuss the lysine acetylation as a potential target for fungal infection treatment and drug target discovery.
Topics: Acetylation; Aspergillosis; Aspergillus; Drug Discovery; Humans; Lysine; Pharmaceutical Preparations; Protein Processing, Post-Translational
PubMed: 32170592
DOI: 10.1007/s42770-020-00253-w -
Natural Product Reports Jun 2018Covering: up to February 2017 Various fungi of the genera Aspergillus, Penicillium, and Malbranchea produce prenylated indole alkaloids possessing a... (Review)
Review
Covering: up to February 2017 Various fungi of the genera Aspergillus, Penicillium, and Malbranchea produce prenylated indole alkaloids possessing a bicyclo[2.2.2]diazaoctane ring system. After the discovery of distinct enantiomers of the natural alkaloids stephacidin A and notoamide B, from A. protuberus MF297-2 and A. amoenus NRRL 35660, another fungi, A. taichungensis, was found to produce their diastereomers, 6-epi-stephacidin A and versicolamide B, as major metabolites. Distinct enantiomers of stephacidin A and 6-epi-stephacidin A may be derived from a common precursor, notoamide S, by enzymes that form a bicyclo[2.2.2]diazaoctane core via a putative intramolecular hetero-Diels-Alder cycloaddition. This review provides our current understanding of the structural and stereochemical homologies and disparities of these alkaloids. Through the deployment of biomimetic syntheses, whole-genome sequencing, and biochemical studies, a unified biogenesis of both the dioxopiperazine and the monooxopiperazine families of prenylated indole alkaloids constituted of bicyclo[2.2.2]diazaoctane ring systems is presented.
Topics: Aquatic Organisms; Aspergillus; Fungi; Indole Alkaloids; Molecular Structure; Prenylation; Stereoisomerism
PubMed: 29632911
DOI: 10.1039/c7np00042a -
Journal of Zhejiang University.... Oct 2008Aflatoxins produced primarily by two closely related fungi, Aspergillus flavus and Aspergillus parasiticus, are mutagenic and carcinogenic in animals and humans. Of many... (Review)
Review
Aflatoxins produced primarily by two closely related fungi, Aspergillus flavus and Aspergillus parasiticus, are mutagenic and carcinogenic in animals and humans. Of many approaches investigated to manage aflatoxin contamination, biological control method has shown great promise. Numerous organisms, including bacteria, yeasts and nontoxigenic fungal strains of A. flavus and A. parasiticus, have been tested for their ability in controlling aflatoxin contamination. Great successes in reducing aflatoxin contamination have been achieved by application of nontoxigenic strains of A. flavus and A. parasiticus in fields of cotton, peanut, maize and pistachio. The nontoxigenic strains applied to soil occupy the same niches as the natural occurring toxigenic strains. They, therefore, are capable of competing and displacing toxigenic strains. In this paper, we review recent development in biological control of aflatoxin contamination.
Topics: Aflatoxins; Animals; Aspergillus; Aspergillus flavus; Food Contamination; Herbicides; Humans; Pest Control, Biological; Soil Microbiology; Species Specificity
PubMed: 18837105
DOI: 10.1631/jzus.B0860003 -
International Journal of Molecular... Oct 2023Worldwide, huge amounts of plastics are being introduced into the ecosystem, causing environmental pollution. Generally, plastic biodegradation in the ecosystem takes...
Worldwide, huge amounts of plastics are being introduced into the ecosystem, causing environmental pollution. Generally, plastic biodegradation in the ecosystem takes hundreds of years. Hence, the isolation of plastic-biodegrading microorganisms and finding optimum conditions for their action is crucial. The aim of the current study is to isolate plastic-biodegrading fungi and explore optimum conditions for their action. Soil samples were gathered from landfill sites; 18 isolates were able to grow on SDA. Only 10 isolates were able to the degrade polyvinyl chloride (PVC) polymer. Four isolates displayed promising depolymerase activity. Molecular identification revealed that three isolates belong to genus , and one isolate was sp. Three isolates showed superior PVC-biodegrading activity (-2, -3 and ) using weight reduction analysis and SEM. Two strains and showed optimum growth at 40 °C, while the last strain grew better at 30 °C. Two isolates grew better at pH 8-9, and the other two isolates grow better at pH 4. Maximal depolymerase activity was monitored at 50 °C, and at slightly acidic pH in most isolates, FeCl significantly enhanced depolymerase activity in two isolates. In conclusion, the isolated fungi have promising potential to degrade PVC and can contribute to the reduction of environmental pollution in eco-friendly way.
Topics: Aspergillus fumigatus; Malassezia; Polyvinyl Chloride; Ecosystem; Fungi; Aspergillus; Biodegradation, Environmental
PubMed: 37895132
DOI: 10.3390/ijms242015452 -
Revista Do Instituto de Medicina... Sep 2015During recent decades, antifungal susceptibility testing has become standardized and nowadays has the same role of the antibacterial susceptibility testing in... (Review)
Review
During recent decades, antifungal susceptibility testing has become standardized and nowadays has the same role of the antibacterial susceptibility testing in microbiology laboratories. American and European standards have been developed, as well as equivalent commercial systems which are more appropriate for clinical laboratories. The detection of resistant strains by means of these systems has allowed the study and understanding of the molecular basis and the mechanisms of resistance of fungal species to antifungal agents. In addition, many studies on the correlation of in vitro results with the outcome of patients have been performed, reaching the conclusion that infections caused by resistant strains have worse outcome than those caused by susceptible fungal isolates. These studies have allowed the development of interpretative breakpoints for Candida spp. and Aspergillus spp., the most frequent agents of fungal infections in the world. In summary, antifungal susceptibility tests have become essential tools to guide the treatment of fungal diseases, to know the local and global disease epidemiology, and to identify resistance to antifungals.
Topics: Antifungal Agents; Aspergillus; Candida; Drug Resistance, Fungal; Humans; Microbial Sensitivity Tests
PubMed: 26465371
DOI: 10.1590/S0036-46652015000700011 -
Journal of Microbiology and... Apr 2020This study was designed to synthesize triglycerol monolaurate (TGML) with Lipozyme 435 as the catalyst, and explore its effects on the growth of () and () and the...
This study was designed to synthesize triglycerol monolaurate (TGML) with Lipozyme 435 as the catalyst, and explore its effects on the growth of () and () and the secretion of aflatoxin b1. The highest content of TGML (49.76%) was obtained at a molar ratio of triglycerol to lauric acid of 1.08, a reaction temperature of 84.93°C, a reaction time of 6 h and an enzyme dosage of 1.32%. After purification by molecular distillation combined with the washes with ethyl acetate and water, the purity of TGML reached 98.3%. Through characterization by electrospray-ionization mass spectrometry, infrared spectrum and nuclear magnetic resonance, the structure of TGML was identified as a linear triglycerol combined with lauroyl at the end. Finally, the inhibitory effects of TGML on the growths of and and the secretion of aflatoxin b1 were evaluated by measuring the colony diameter, the inhibition rate of mycelial growth and the content of mycotoxin in the media. The results indicated that TGML had a stronger inhibitory effects on colony growth and mycelial development of both toxic molds compared to sodium benzoate and potassium sorbate, and the secretions of toxins from and were completely suppressed when adding TGML at 10 and 5 mM, respectively. Based on the above results, TGML may be used as a substitute for traditional antifungal agents in the food industry.
Topics: Aflatoxin B1; Antifungal Agents; Aspergillus; Aspergillus flavus; Esterification; Laurates; Lipase; Mycelium; Temperature; Triglycerides
PubMed: 31986567
DOI: 10.4014/jmb.1910.10043 -
Biocontrol Science 2017The antiaflatoxigenic and antifungal activities of essential oils (EOs) of finger root (Boesenbergia rotunda (L.) Mansf.), pine (Pinus pinaster), rosewood (Aniba...
The antiaflatoxigenic and antifungal activities of essential oils (EOs) of finger root (Boesenbergia rotunda (L.) Mansf.), pine (Pinus pinaster), rosewood (Aniba rosaedora), Siam benzoin (Styrax tonkinensis), Thai moringa (Moringa oleifera), and ylang ylang (Cananga odorata) were tested for Aspergillus parasiticus and Aspergillus flavus in potato dextrose broth. Aflatoxin B (AFB) was extracted from culture using a QuEChERS-based extraction procedure and analyzed with high performance liquid chromatography (HPLC) coupled to a fluorescence detector. EO of pine showed the greatest inhibition of growth and AFB production of A. parasiticus, followed by EOs of rosewood, finger root, Siam benzoin, and ylang ylang. EO of finger root gave the best inhibitory effects on A. flavus, followed by EOs of rosewood, pine, ylang ylang, and Siam benzoin. EO of Thai moringa did not show any significant inhibition of aflatoxigenic fungi. The antiaflatoxigenic activities of EOs correlated with their antifungal activities in the dosedependent manner. Comparison of the application of the five selected EOs in peanut pods by direct and vapor exposure indicated that the AFB production inhibitory effects of the five EOs by direct exposure were faster and more effective than by vapor exposure. EO of finger root showed the best inhibition of AFB production of A. flavus in peanut pods by direct exposure, followed by EOs of pine, rosewood, ylang ylang, and Siam benzoin.
Topics: Aflatoxin B1; Antifungal Agents; Arachis; Aspergillus; Aspergillus flavus; Culture Media; Oils, Volatile
PubMed: 28367868
DOI: 10.4265/bio.22.31 -
Biomolecules Feb 2021Food and feed safety are of paramount relevance in everyday life. The awareness that different chemicals, e.g., those largely used in agriculture, could present both...
Food and feed safety are of paramount relevance in everyday life. The awareness that different chemicals, e.g., those largely used in agriculture, could present both environmental problems and health hazards, has led to a large limitation of their use. Chemicals were also the main tool in a control of fungal pathogens and their secondary metabolites, mycotoxins. There is a drive to develop more environmentally friendly, "green", approaches to control mycotoxin contamination of foodstuffs. Different mushroom metabolites showed the potential to act as control agents against mycotoxin production. The use of a polysaccharide, Tramesan, extracted from the basidiomycete , for controlling biosynthesis of aflatoxin B1 and ochratoxin A, has been previously discussed. In this study, oligosaccharides obtained from Tramesan were evaluated. The purified exopolysaccharide of was partially hydrolyzed and separated by chromatography into fractions from disaccharides to heptasaccharides. Each fraction was individually tested for mycotoxin inhibition in and . Fragments smaller than seven units showed no significant effect on mycotoxin inhibition; heptasaccharides showed inhibitory activity of up to 90% in both fungi. These results indicated that these oligosaccharides could be used as natural alternatives to crop protection chemicals for controlling these two mycotoxins.
Topics: Aspergillus; Aspergillus flavus; Food Contamination; Hydrolysis; Mycotoxins; Oligosaccharides; Spectrum Analysis; Structure-Activity Relationship; Trametes
PubMed: 33567727
DOI: 10.3390/biom11020243