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Studies in Mycology Dec 2022series members occur in a wide range of environments and substrates such as indoor environments, food, clinical materials, soil, caves, marine or hypersaline...
series members occur in a wide range of environments and substrates such as indoor environments, food, clinical materials, soil, caves, marine or hypersaline ecosystems. The taxonomy of the series has undergone numerous re-arrangements including a drastic reduction in the number of species and subsequent recovery to 17 species in the last decade. The identification to species level is however problematic or impossible in some isolates even using DNA sequencing or MALDI-TOF mass spectrometry indicating a problem in the definition of species boundaries. To revise the species limits, we assembled a large dataset of 518 strains. From these, a total of 213 strains were selected for the final analysis according to their calmodulin () genotype, substrate and geography. This set was used for phylogenetic analysis based on five loci (, , , , ). Apart from the classical phylogenetic methods, we used multispecies coalescence (MSC) model-based methods, including one multilocus method (STACEY) and five single-locus methods (GMYC, bGMYC, PTP, bPTP, ABGD). Almost all species delimitation methods suggested a broad species concept with only four species consistently supported. We also demonstrated that the currently applied concept of species is not sustainable as there are incongruences between single-gene phylogenies resulting in different species identifications when using different gene regions. Morphological and physiological data showed overall lack of good, taxonomically informative characters, which could be used for identification of such a large number of existing species. The characters expressed either low variability across species or significant intraspecific variability exceeding interspecific variability. Based on the above-mentioned results, we reduce series to four species, namely , and , and the remaining species are synonymized with either or . The revised descriptions of the four accepted species are provided. They can all be identified by any of the five genes used in this study. Despite the large reduction in species number, identification based on phenotypic characters remains challenging, because the variation in phenotypic characters is high and overlapping among species, especially between and . Similar to the 17 narrowly defined species, the four broadly defined species do not have a specific ecology and are distributed worldwide. We expect that the application of comparable methodology with extensive sampling could lead to a similar reduction in the number of cryptic species in other extensively studied species complexes and other fungal genera. Sklenář F, Glässnerová K, Jurjević Ž, Houbraken J, Samson RA, Visagie CM, Yilmaz N, Gené J, Cano J, Chen AJ, Nováková A, Yaguchi T, Kolařík M, Hubka V (2022). Taxonomy of series : species reduction and lessons learned about intraspecific variability. : 53-93. doi: 10.3114/sim.2022.102.02.
PubMed: 36760461
DOI: 10.3114/sim.2022.102.02 -
Marine Life Science & Technology 2023Further insights on the secondary metabolites of a soft coral-derived fungus under the guidance of MS/MS-based molecular networking led to the isolation of seven known...
Targeted isolation of antitubercular cycloheptapeptides and an unusual pyrroloindoline-containing new analog, asperpyrroindotide A, using LC-MS/MS-based molecular networking.
UNLABELLED
Further insights on the secondary metabolites of a soft coral-derived fungus under the guidance of MS/MS-based molecular networking led to the isolation of seven known cycloheptapeptides, namely, asperversiamides A-C (-) and asperheptatides A-D (-) and an unusual pyrroloindoline-containing new cycloheptapeptide, asperpyrroindotide A (). The structure of was elucidated by comprehensive spectroscopic data analysis, and its absolute configuration was determined by advanced Marfey's method. The semisynthetic transformation of into was successfully achieved and the reaction conditions were optimized. Additionally, a series of new derivatives (-) of asperversiamide A () was semi-synthesized and their anti-tubercular activities were evaluated against H37Ra. The preliminary structure-activity relationships revealed that the serine hydroxy groups and the tryptophan residue are important to the activity.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s42995-022-00157-8.
PubMed: 36713278
DOI: 10.1007/s42995-022-00157-8 -
International Journal of Biological... Feb 2023Until now, relatively little is known about marine-derived fungal polysaccharides and their activities. Exopolysaccharide AVP141-A was isolated from the broth of...
Until now, relatively little is known about marine-derived fungal polysaccharides and their activities. Exopolysaccharide AVP141-A was isolated from the broth of marine-derived fungus Aspergillus versicolor SCAU141 and purified by Diethylaminoethyl-Sepharose Fast Flow and Sephadex G-100. The structural characteristics of AVP141-A was studied by chemical analysis together with high-performance gel permeation chromatography, ion chromatography, Fourier-transform infrared spectroscopy, gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy. The results showed that AVP141-A with the molecular weight of 5.10 kDa was mainly composed of →4)-α-D-Glcp-(1→, branched by α-D-Glcp-(1→ and →6)-α-D-Glcp-(1→ at C-6 positions of the glucan backbone. In particular, sulfate ester (approximately 3.62 %) was found in AVP141-A, which was frequently considered to occur in marine-derived microbial polysaccharides rather than other microbial polysaccharides. Furthermore, AVP141-A significantly enhanced the activity of the inflammatory factors NO, COX-2 and TNF-α in RAW264.7 macrophages by activating the MAPK/p38 and NF-κB/p65 pathways. In addition, metabolomic analysis revealed that most of the pathways with significant changes in RAW264.7 macrophages treated with AVP141-A were amino acid-related pathways, and arginine was the characteristic metabolite. In conclusion, this study identified AVP141-A as a marine fungus-derived sulfated exopolysaccharide with potential for development as an immune activator.
Topics: Polysaccharides; Gas Chromatography-Mass Spectrometry; Aspergillus; Fungal Polysaccharides; Fungi; Molecular Weight; Spectroscopy, Fourier Transform Infrared
PubMed: 36535356
DOI: 10.1016/j.ijbiomac.2022.12.127 -
Journal of Fungi (Basel, Switzerland) Nov 2022Onychomycosis is a fungal disease of the nail that is found worldwide and is difficult to diagnose accurately. This study used metagenomics to investigate the...
Onychomycosis is a fungal disease of the nail that is found worldwide and is difficult to diagnose accurately. This study used metagenomics to investigate the microbiology of 18 clinically diagnosed mycotic nails and two normal nails for fungi and bacteria using the ITS2 and 16S loci. Four mycotic nails were from Bass Coast, six from Melbourne Metropolitan and eight from Shepparton, Victoria, Australia. The mycotic nails were photographed and metagenomically analysed. The ITS2 sequences for and averaged over 90% of hits in 14/18 nails. The high abundance of sequences of a single dermatophyte, compared to all other fungi in a single nail, made it the most likely infecting agents (MLIA). and interdigitale/mentagrophytes were found in Bass Coast and Shepparton while only was found in Melbourne. Two nails with mixed with high abundance non-dermatophyte moulds (NDMs) (, ) were also observed. The two control nails contained chiefly and . For bacteria, was in every nail and was the most abundant, including the control nails, with an overall mean rate of 66.01%. , , and also featured.
PubMed: 36422019
DOI: 10.3390/jof8111198 -
Microbial Biotechnology Jan 2023Aspergillus genus is a key component in fermentation and food processing. However, sterigmatocystin (STE)-a mycotoxin produced by several species of Aspergillus-limits...
Aspergillus genus is a key component in fermentation and food processing. However, sterigmatocystin (STE)-a mycotoxin produced by several species of Aspergillus-limits the use of some Aspergillus species (such as Aspergillus versicolor, Aspergillus inflatus, and Aspergillus parasiticus) because of its toxicity and carcinogenicity. Here, we engineered an STE-free Aspergillus versicolor strain based on genome mining techniques. We sequenced and assembled the Aspergillus versicolor D5 genome (34.52 Mb), in which we identified 16 scaffolds and 54 biosynthetic gene clusters (BGCs). We silenced cytochrome P450 coding genes STC17 and STC27 by insertional inactivation. The production of STE in the Δstc17 mutant strain was increased by 282% but no STE was detected in the Δstc27 mutant. Metabolites of Δstc27 mutant exhibited growth-promoting effect on plants. Our study makes significant progress in improving the application of some Aspergillus strains by restricting their production of toxic and carcinogenic compounds.
Topics: Sterigmatocystin; Aspergillus; Secondary Metabolism; Fermentation
PubMed: 36415948
DOI: 10.1111/1751-7915.14176 -
Molecules (Basel, Switzerland) Oct 2022Marine fungi sp. is an important source of natural active lead compounds with biological and chemical diversity, of which sesquiterpenoids are an extremely important... (Review)
Review
Marine fungi sp. is an important source of natural active lead compounds with biological and chemical diversity, of which sesquiterpenoids are an extremely important class of bioactive secondary metabolites. In this paper, we review the sources, chemical structures, bioactivity, biosynthesis, and druggability evaluation of sesquiterpenoids discovered from marine fungi sp. since 2008. The species involved include mainly , , , , , and so on, which originate from sponges, marine sediments, algae, mangroves, and corals. In recent years, 268 sesquiterpenoids were isolated from secondary metabolites of marine sp., 131 of which displayed bioactivities such as antitumor, antimicrobial, anti-inflammatory, and enzyme inhibitory activity. Furthermore, the main types of active sesquiterpenoids are bisabolanes, followed by drimanes, nitrobenzoyl, etc. Therefore, these novel sesquiterpenoids will provide a large number of potential lead compounds for the development of marine drugs.
Topics: Animals; Aspergillus; Sesquiterpenes; Fungi; Anti-Infective Agents; Anthozoa
PubMed: 36364202
DOI: 10.3390/molecules27217376 -
Phytochemistry Jan 2023Nicotiana tabacum (tobacco) has attracted interest as one of the most economically important industrial crops widely cultivated in China, whose dried leaves are...
Nicotiana tabacum (tobacco) has attracted interest as one of the most economically important industrial crops widely cultivated in China, whose dried leaves are popularly consumed medicinally and recreationally by human societies. In this study, five undescribed alkaloids derivatives, isoaspergillines A-E, together with eight known alkaloids, notoamide D, (1R,4S)-4-benzyl-1-isopropyl-2,4-dihydro-1H-pyrazino-[2,1-b]quinazoline-3,6-dione, protuboxepin K, notoamide C, notoamide M, deoxybrevianamide E, cyclo (D-Pro-L-Trp), and versicolamide B, were obtained from the culture of the Nicotiana tabacum-derived fungus Aspergillus versicolor. Their structures were mainly elucidated through comprehensive analyses of spectroscopic data. Bioactivity evaluation of all isolated compounds revealed that isoaspergilline A and notoamide M exhibited anti-TMV activities with IC values of 20.0 and 22.8 μM, respectively. Molecular docking suggested that isoaspergilline A and notoamide M were well located into the active site of anti-TMV by interacting with SER138, SER143, and ASN73 residues. This study enlightens the therapeutic potential of the endophytic fungus A. versicolor and it is helpful to find undescribed anti-TMV activity inhibitors, as well as searching for new anti-TMV candidates from natural sources.
Topics: Humans; Nicotiana; Molecular Docking Simulation; China
PubMed: 36334789
DOI: 10.1016/j.phytochem.2022.113485 -
Frontiers in Microbiology 2022The use of morphology to diagnose invasive mould infections in China still faces substantial challenges, which often leads to delayed diagnosis or misdiagnosis. We...
The use of morphology to diagnose invasive mould infections in China still faces substantial challenges, which often leads to delayed diagnosis or misdiagnosis. We developed a model called XMVision Fungus AI to identify mould infections by training, testing, and evaluating a ResNet-50 model. Our research achieved the rapid identification of nine common clinical moulds: complex, complex, complex, complex, , , , spp., and spp. In our study, the adaptive image contrast enhancement enabling XMVision Fungus AI as a promising module by effectively improve the identification performance. The overall identification accuracy of XMVision Fungus AI was up to 93.00% (279/300), which was higher than that of human readers. XMVision Fungus AI shows intrinsic advantages in the identification of clinical moulds and can be applied to improve human identification efficiency through training. Moreover, it has great potential for clinical application because of its convenient operation and lower cost. This system will be suitable for primary hospitals in China and developing countries.
PubMed: 36312928
DOI: 10.3389/fmicb.2022.1021236 -
Food Microbiology Feb 2023This study aimed to isolate and identify fungal species involved in sliced bread spoilage, and to evaluate their susceptibility to antifungal proteins of fungal origin...
This study aimed to isolate and identify fungal species involved in sliced bread spoilage, and to evaluate their susceptibility to antifungal proteins of fungal origin (AFPs). Proteins include PdAfpB from Penicillium digitatum and PeAfpA, PeAfpB and PeAfpC from Penicillium expansum. Based on morphological criteria, a group of sixteen fungal isolates were selected and subsequently identified at the species level using sequence analysis. Penicillium species, the predominant mycobiota, were identified based on a combined phylogenetic analysis using ITS and β-tubulin sequences, being P. roqueforti, P. brevicompactum, P. chrysogenum and P. crustosum the most abundant species. Aspergillus versicolor, Aspergillus niger and Bissochlamys spectabilis were also identified. Regarding the antifungal activity of AFPs, PdAfpB and PeAfpA were the most potent proteins since the growth of most of tested fungi was completely inhibited by concentrations ranging from 2 to 32 μg/mL. PeAfpB showed moderate antifungal activity, whereas PeAfpC was the least active protein. The best in vitro AFPs, PdAfpB and PeAfpA, were also evaluated in in situ protection assays against P. roqueforti. PdAfpB provoked a clear reduction of P. roqueforti growth in sliced bread samples, suggesting that this AFP has a protective effect on bread. This study underlines the potential of the AFPs tested, in particular PdAfpB, as alternative antifungal agents for extending sliced bread shelf life.
Topics: Bread; Antifungal Agents; Phylogeny; Penicillium; Aspergillus niger; Fungi
PubMed: 36309457
DOI: 10.1016/j.fm.2022.104142 -
Environmental Research Jan 2023Pigeon breeding is associated with exposure to airborne microorganisms and endotoxin and with symptoms of the airways. Antibiotic resistance is a threat to human health....
Pigeon breeding is associated with exposure to airborne microorganisms and endotoxin and with symptoms of the airways. Antibiotic resistance is a threat to human health. Some pigeons participate in national and international indoor exhibitions. This study aims to obtain knowledge about the potential human exposure to dust, endotoxin, fungi, and bacteria including the methicillin-resistant Staphylococcus aureus (MRSA) in a pigeon exhibition in Denmark. In walking areas for visitors, airborne microorganisms in different size fractions able to enter the airways were sampled and following identified. The average concentrations were: 5000 cfu fungi/m, 1.8 × 10 cfu bacteria/m, 37 endotoxin units/m, and 0.18 mg dust/m air with the highest concentrations in-between rows with pigeon cages. The fungal species Wallemia sp. and Aspergillus versicolor and the bacterial species S. equorum and S. aureus were found in high concentrations. MRSA spa type t034 described to be associated with livestock was found in the air. Most of the S. aureus was present in the size fraction of 1.1-2.1 μm, which are particles able to enter the human terminal bronchi. In conclusion, fungi, bacteria, and endotoxin, respectively, were found in concentrations 10, 2000, and 200 times higher than outdoor references. The airborne bacteria in the exhibition were mainly species found previously in pigeon coops showing that the pigeons are the sources of exposure. The presence of airborne MRSA in the pigeon exhibition highlights the importance of also considering this environment as a potential place of exchange of resistant bacteria between animals and between animals and humans.
Topics: Animals; Humans; Dust; Methicillin-Resistant Staphylococcus aureus; Columbidae; Endotoxins; Staphylococcus aureus; Occupational Exposure; Bacteria; Fungi; Air Microbiology
PubMed: 36306875
DOI: 10.1016/j.envres.2022.114642