Journal of Fungi

10 pages, 2879 KiB

Open AccessArticle

Perturbations in the Heme and Siroheme Biosynthesis Pathways Causing Accumulation of Fluorescent Free Base Porphyrins and Auxotrophy in Ogataea Yeasts

by Azamat V. Karginov, Alexander I. Alexandrov, Vitaly V. Kushnirov and Michael O. Agaphonov

J. Fungi 2021, 7(10), 884; https://doi.org/10.3390/jof7100884 - 19 Oct 2021

Cited by 4 | Viewed by 1816

Abstract

The biosynthesis of cyclic tetrapyrrol chromophores such as heme, siroheme, and chlorophyll involves the formation of fluorescent porphyrin precursors or compounds, which become fluorescent after oxidation. To identify Ogataea polymorpha mutations affecting the final steps of heme or siroheme biosynthesis, we performed a [...] Read more.

The biosynthesis of cyclic tetrapyrrol chromophores such as heme, siroheme, and chlorophyll involves the formation of fluorescent porphyrin precursors or compounds, which become fluorescent after oxidation. To identify Ogataea polymorpha mutations affecting the final steps of heme or siroheme biosynthesis, we performed a search for clones with fluorescence characteristic of free base porphyrins. One of the obtained mutants was defective in the gene encoding a homologue of Saccharomyces cerevisiae Met8 responsible for the last two steps of siroheme synthesis. Same as the originally obtained mutation, the targeted inactivation of this gene in O. polymorpha and O. parapolymorpha led to increased porphyrin fluorescence and methionine auxotrophy. These features allow the easy isolation of Met8-defective mutants and can potentially be used to construct auxotrophic strains in various yeast species. Besides MET8, this approach also identified the HEM3 gene encoding porphobilinogen deaminase, whose increased dosage led to free base porphyrin accumulation. Full article

(This article belongs to the Special Issue Yeast Genetics 2021)

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Graphical abstract

22 pages, 4285 KiB

Open AccessArticle

Arabidopsis Toxicos en Levadura 12 (ATL12): A Gene Involved in Chitin-Induced, Hormone-Related and NADPH Oxidase-Mediated Defense Responses

by Feng Kong, Tingwei Guo and Katrina M. Ramonell

J. Fungi 2021, 7(10), 883; https://doi.org/10.3390/jof7100883 - 19 Oct 2021

Cited by 5 | Viewed by 2217

Abstract

Plants, as sessile organisms, have evolved complex systems to respond to changes in environmental conditions. Chitin is a Pathogen-Associated-Molecular Pattern (PAMP) that exists in the fungal cell walls, and can be recognized by plants and induce plant pattern-triggered immunity (PTI). Our previous studies [...] Read more.

Plants, as sessile organisms, have evolved complex systems to respond to changes in environmental conditions. Chitin is a Pathogen-Associated-Molecular Pattern (PAMP) that exists in the fungal cell walls, and can be recognized by plants and induce plant pattern-triggered immunity (PTI). Our previous studies showed that Arabidopsis Toxicos en Levadura 12 (ATL12) is highly induced in response to fungal infection and chitin treatment. We used the model organism Arabidopsis thaliana to characterize ATL12 and explore its role in fungal defense. Histochemical staining showed that pATL12-GUS was continually expressed in roots, leaves, stems, and flowers. Subcellular co-localization of the ATL12-GFP fusion protein with the plasma membrane-mcherry marker showed that ATL12 localizes to the plasma membrane. Mutants of atl12 are more susceptible to Golovinomyces cichoracearum infection, while overexpression of ATL12 increased plant resistance to the fungus. ATL12 is highly induced by chitin after two hours of treatment and ATL12 may act downstream of MAPK cascades. Additionally, 3,3′-diaminobenzidine (DAB) staining indicated that atl12 mutants generate less reactive oxygen species compared to wild-type Col-0 plants and RT-PCR indicated that ATL12-regulated ROS production may be linked to the expression of respiratory burst oxidase homolog protein D/F (AtRBOHD/F). Furthermore, we present evidence that ATL12 expression is upregulated after treatment with both salicylic acid and jasmonic acid. Taken together, these results suggest a role for ATL12 in crosstalk between hormonal, chitin-induced, and NADPH oxidase-mediated defense responses in Arabidopsis. Full article

(This article belongs to the Section Fungal Genomics, Genetics and Molecular Biology)

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11 pages, 959 KiB

Open AccessArticle

Data-Mining Techniques: A New Approach to Identifying the Links among Hybrid Strains of Pleurotus with Culture Media

by Fabricio Guevara-Viejó, Juan Diego Valenzuela-Cobos, Purificación Vicente-Galindo and Purificación Galindo-Villardón

J. Fungi 2021, 7(10), 882; https://doi.org/10.3390/jof7100882 - 19 Oct 2021

Cited by 2 | Viewed by 1548

Abstract

In this study, a data set of mycelial and cultural characteristics of hybrid strains of Pleurotus ostreatus and Pleurotus djamor were analyzed using three data-mining techniques: the K-medoids clustering algorithm, PCA biplot and the association rules algorithm. The characteristics evaluated were as follows: [...] Read more.

In this study, a data set of mycelial and cultural characteristics of hybrid strains of Pleurotus ostreatus and Pleurotus djamor were analyzed using three data-mining techniques: the K-medoids clustering algorithm, PCA biplot and the association rules algorithm. The characteristics evaluated were as follows: maximum velocity; lag phase; biomass; and exopolysaccharides content in the cultivation of 50 hybrid strains of Pleurotus ostreatus and 50 hybrid strains of Pleurotus djamor. Different mixtures of culture media were used to supplement Ecuadorian agricultural products. Data of the parameters obtained in the experimental methods were grouped into four clusters, obtaining a presentation of the hybrid strains of Pleurotus with a higher relation to each characteristic measured. Data-mining tools showed the hybrid strains cultivated on solid-culture media (M1 = malt extract agar and rice flour) and liquid-culture media (L1 = maltose, yeast extract and rice flour) presented the highest mycelial and cultural characteristics. These results are good indicators to improve the industrial production of edible fungi by using rice flour in the cultivation, contributing to the mushroom market and circular economy. Full article

(This article belongs to the Special Issue Edible Mushrooms)

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11 pages, 270 KiB

Open AccessArticle

COVID-19-Associated Invasive Pulmonary Aspergillosis in the Intensive Care Unit: A Case Series in a Portuguese Hospital

by David Ranhel, Ana Ribeiro, Judite Batista, Maria Pessanha, Elisabete Cristovam, Ana Duarte, Ana Dias, Luís Coelho, Filipa Monteiro, Pedro Freire, Cristina Veríssimo, Raquel Sabino and Cristina Toscano

J. Fungi 2021, 7(10), 881; https://doi.org/10.3390/jof7100881 - 19 Oct 2021

Cited by 6 | Viewed by 1763

Abstract

Invasive pulmonary aspergillosis (IPA) has become a recognizable complication in coronavirus disease 2019 (COVID-19) patients admitted to intensive care units (ICUs). Alveolar damage in the context of acute respiratory distress syndrome (ARDS) appears to be the culprit in facilitating fungal invasion in COVID-19 [...] Read more.

Invasive pulmonary aspergillosis (IPA) has become a recognizable complication in coronavirus disease 2019 (COVID-19) patients admitted to intensive care units (ICUs). Alveolar damage in the context of acute respiratory distress syndrome (ARDS) appears to be the culprit in facilitating fungal invasion in COVID-19 patients, leading to a COVID-19-associated pulmonary aspergillosis (CAPA) phenomenon. From November 2020 to 15 February 2021, 248 COVID-19 patients were admitted to our ICUs, of whom ten patients (4% incidence) were classified as either probable (six) or possible (four) CAPA cases. Seven patients had positive cultural results: Aspergillus fumigatus sensu stricto (five), A. terreus sensu stricto (one), and A. welwitschiae (one). Five patients had positive bronchoalveolar lavage (BAL) and galactomannan (GM), and two patients had both positive cultural and GM criteria. All but two patients received voriconazole. Mortality rate was 30%. Strict interpretation of classic IPA definition would have resulted in eight overlooked CAPA cases. Broader diagnostic criteria are essential in this context, even though differentiation between Aspergillus colonization and invasive disease might be more challenging. Herein, we aim to raise awareness of CAPA in view of its potential detrimental outcome, emphasizing the relevance of a low threshold for screening and early antifungal treatment in ARDS patients. Full article

20 pages, 3951 KiB

Open AccessArticle

Morphological and Phylogenetic Appraisal of Novel and Extant Taxa of Stictidaceae from Northern Thailand

by De-Ping Wei, Dhanushka N. Wanasinghe, Eleni Gentekaki, Vinodhini Thiyagaraja, Saisamorn Lumyong and Kevin D. Hyde

J. Fungi 2021, 7(10), 880; https://doi.org/10.3390/jof7100880 - 19 Oct 2021

Cited by 9 | Viewed by 2105

Abstract

Stictidaceae comprises taxa with diverse lifestyles. Many species in this family are drought resistant and important for studying fungal adaptation and evolution. Stictidaceae comprises 32 genera, but many of them have been neglected for decades due to the lack of field collections and [...] Read more.

Stictidaceae comprises taxa with diverse lifestyles. Many species in this family are drought resistant and important for studying fungal adaptation and evolution. Stictidaceae comprises 32 genera, but many of them have been neglected for decades due to the lack of field collections and molecular data. In this study, we introduce a new species Fitzroyomyces hyaloseptisporus and a new combination Fitzroyomycespandanicola. We also provide additional morphological and molecular data for Ostropomyces pruinosellus and O. thailandicus based on new collections isolated from an unidentified woody dicotyledonous host in Chiang Rai, Thailand. Taxonomic conclusions are made with the aid of morphological evidence and phylogenetic analysis of combined LSU, ITS and mtSSU sequence data. Characteristics such as the shape and septation of ascospores and conidia as well as lifestyles among genera of Stictidaceae are discussed. Full article

(This article belongs to the Special Issue Fungal Biodiversity and Ecology 2.0)

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23 pages, 5980 KiB

Open AccessArticle

Identification of Fungal Pathogens to Control Postharvest Passion Fruit (Passiflora edulis) Decays and Multi-Omics Comparative Pathway Analysis Reveals Purple Is More Resistant to Pathogens than a Yellow Cultivar

by Hafiz Muhammad Rizwan, Lin Zhimin, Wiwiek Harsonowati, Abdul Waheed, Yang Qiang, Ahmed Fathy Yousef, Nigarish Munir, Xiaoxia Wei, Sandra S. Scholz, Michael Reichelt, Ralf Oelmüller and Faxing Chen

J. Fungi 2021, 7(10), 879; https://doi.org/10.3390/jof7100879 - 19 Oct 2021

Cited by 12 | Viewed by 5929

Abstract

Production of passion fruit (Passiflora edulis) is restricted by postharvest decay, which limits the storage period. We isolated, identified, and characterized fungal pathogens causing decay in two passion fruit cultivars during two fruit seasons in China. Morphological characteristics and nucleotide sequences [...] Read more.

Production of passion fruit (Passiflora edulis) is restricted by postharvest decay, which limits the storage period. We isolated, identified, and characterized fungal pathogens causing decay in two passion fruit cultivars during two fruit seasons in China. Morphological characteristics and nucleotide sequences of ITS-rDNA regions identified eighteen isolates, which were pathogenic on yellow and purple fruit. Fusarium kyushuense, Fusarium concentricum, Colletotrichum truncatum, and Alternaria alternata were the most aggressive species. Visible inspections and comparative analysis of the disease incidences demonstrated that wounded and non-wounded yellow fruit were more susceptible to the pathogens than the purple fruit. Purple cultivar showed higher expression levels of defense-related genes through expression and metabolic profiling, as well as significantly higher levels of their biosynthesis pathways. We also found fungi with potential beneficial features for the quality of fruits. Our transcriptomic and metabolomics data provide a basis to identify potential targets to improve the pathogen resistance of the susceptible yellow cultivar. The identified fungi and affected features of the fruit of both cultivars provide important information for the control of pathogens in passion fruit industry and postharvest storage. Full article

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11 pages, 317 KiB

Open AccessArticle

International Multicentre Study of Candida auris Infections

by Nirav Pandya, Yasemin Cag, Nenad Pandak, Abdullah Umut Pekok, Aruna Poojary, Folusakin Ayoade, Teresa Fasciana, Anna Giammanco, Hulya Caskurlu, Dhanji P. Rajani, Yogesh Kumar Gupta, Ilker Inanc Balkan, Ejaz Ahmed Khan and Hakan Erdem

J. Fungi 2021, 7(10), 878; https://doi.org/10.3390/jof7100878 - 19 Oct 2021

Cited by 17 | Viewed by 3094

Abstract

Background:Candida auris has emerged globally as a multi-drug resistant yeast and is commonly associated with nosocomial outbreaks in ICUs. Methods: We conducted a retrospective observational multicentre study to determine the epidemiology of C. auris infections, its management strategies, patient outcomes, and infection [...] Read more.

Background:Candida auris has emerged globally as a multi-drug resistant yeast and is commonly associated with nosocomial outbreaks in ICUs. Methods: We conducted a retrospective observational multicentre study to determine the epidemiology of C. auris infections, its management strategies, patient outcomes, and infection prevention and control practices across 10 centres from five countries. Results: Significant risk factors for C. auris infection include the age group of 61–70 years (39%), recent history of ICU admission (63%), diabetes (63%), renal failure (52%), presence of CVC (91%) and previous history of antibiotic treatment (96%). C. auris was commonly isolated from blood (76%). Echinocandins were the most sensitive drugs. Most common antifungals used for treatment were caspofungin (40%), anidulafungin (28%) and micafungin (15%). The median duration of treatment was 20 days. Source removal was conductedin 74% patients. All-cause crude mortality rate after 30 days was 37%. Antifungal therapy was associated with a reduction in mortality (OR:0.27) and so was source removal (OR:0.74). Contact isolation precautions were followed in 87% patients. Conclusions:C. auris infection carries a high risk for associated mortality. The organism is mainly resistant to most azoles and even amphotericin-B. Targeted antifungal therapy, mainly an echinocandin, and source control are the prominent therapeutic approaches. Full article

(This article belongs to the Special Issue Invasive Candidiasis)

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11 pages, 1818 KiB

Open AccessCase Report

Mixed Etiology COVID-19 Associated Pulmonary Aspergillosis (CAPA)—A Case Report and Brief Review of the Literature

by Dan Alexandru Toc, Carmen Costache, Alexandru Botan, Razvan Marian Mihaila, Ioana Alina Colosi, Sandor Botond Buksa and Roxana Mihaela Chiorescu

J. Fungi 2021, 7(10), 877; https://doi.org/10.3390/jof7100877 - 18 Oct 2021

Cited by 10 | Viewed by 2834

Abstract

The SARS-CoV-2 pandemic has proved to be a significant risk addition for invasive infections with Aspergillus. Even though there are plenty of data about the COVID-19-associated pulmonary aspergillosis (CAPA), especially involving Aspergillus fumigatus, recent studies are presenting cases of CAPA involving more [...] Read more.

The SARS-CoV-2 pandemic has proved to be a significant risk addition for invasive infections with Aspergillus. Even though there are plenty of data about the COVID-19-associated pulmonary aspergillosis (CAPA), especially involving Aspergillus fumigatus, recent studies are presenting cases of CAPA involving more than one species of Aspergillus. We report the first case of a SARS-CoV-2 patient associating co-infection with, most likely, Aspergillus section Fumigati and Aspergillus section Flavi from Romania, and we review the existing medical literature in order to shed light upon mixed etiology cases of CAPA. Since mortality remains high in these cases, there is an acute need for more information about the interaction between SARS-CoV-2 and Aspergillus spp., and the therapies for CAPA. The emerging number of cases and the high mortality rate must be considered an incentive for future research. Full article

(This article belongs to the Special Issue Respiratory Fungal Infections)

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18 pages, 2754 KiB

Open AccessArticle

Potent and Selective Inhibitors of Human Monoamine Oxidase A from an Endogenous Lichen Fungus Diaporthe mahothocarpus

by Geum Seok Jeong, Prima F. Hillman, Myung-Gyun Kang, Sungbo Hwang, Jong-Eun Park, Sang-Jip Nam, Daeui Park and Hoon Kim

J. Fungi 2021, 7(10), 876; https://doi.org/10.3390/jof7100876 - 18 Oct 2021

Cited by 6 | Viewed by 1861

Abstract

Using 126 endogenous lichen fungus (ELF) extracts, inhibitory activities against monoamine oxidases (MAOs) and cholinesterases (ChEs) were evaluated. Among them, extract ELF29 of the endogenous fungus Diaporthe mahothocarpus of the lichen Cladonia symphycarpia showed the highest inhibitory activity against hMAO-A. Compounds alternariol (AT), [...] Read more.

Using 126 endogenous lichen fungus (ELF) extracts, inhibitory activities against monoamine oxidases (MAOs) and cholinesterases (ChEs) were evaluated. Among them, extract ELF29 of the endogenous fungus Diaporthe mahothocarpus of the lichen Cladonia symphycarpia showed the highest inhibitory activity against hMAO-A. Compounds alternariol (AT), 5′-hydroxy-alternariol (HAT), and mycoepoxydiene (MED), isolated from the extract, had potent inhibitory activities against hMAO-A with IC₅₀ values of 0.020, 0.31, and 8.68 µM, respectively. AT, HAT, and MED are reversible competitive inhibitors of hMAO-A with K_i values of 0.0075, 0.116, and 3.76 µM, respectively. The molecular docking studies suggested that AT, HAT, and MED had higher binding affinities for hMAO-A (−9.1, −6.9, and −5.6 kcal/mol, respectively) than for hMAO-B (−6.3, −5.2, and −3.7 kcal/mol, respectively). The relative tight binding might result from a hydrogen bond interaction of the three compounds with a Tyr444 residue in hMAO-A, whereas no hydrogen bond interaction was proposed in hMAO-B. In silico pharmacokinetics, the three compounds showed high gastrointestinal absorption without violating Lipinski’s five rules, but only MED showed high probability to cross the blood–brain barrier. These results suggest that AT, HAT, and MED are candidates for treating neuropsychiatric disorders, such as depression and cardiovascular disease. Full article

(This article belongs to the Special Issue Fungi for Biotechnological Application and Environmental Cleanup)

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25 pages, 1192 KiB

Open AccessReview

Role of Protein Glycosylation in Interactions of Medically Relevant Fungi with the Host

by Manuela Gómez-Gaviria, Ana P. Vargas-Macías, Laura C. García-Carnero, Iván Martínez-Duncker and Héctor M. Mora-Montes

J. Fungi 2021, 7(10), 875; https://doi.org/10.3390/jof7100875 - 18 Oct 2021

Cited by 12 | Viewed by 4062

Abstract

Protein glycosylation is a highly conserved post-translational modification among organisms. It plays fundamental roles in many biological processes, ranging from protein trafficking and cell adhesion to host–pathogen interactions. According to the amino acid side chain atoms to which glycans are linked, protein glycosylation [...] Read more.

Protein glycosylation is a highly conserved post-translational modification among organisms. It plays fundamental roles in many biological processes, ranging from protein trafficking and cell adhesion to host–pathogen interactions. According to the amino acid side chain atoms to which glycans are linked, protein glycosylation can be divided into two major categories: N-glycosylation and O-glycosylation. However, there are other types of modifications such as the addition of GPI to the C-terminal end of the protein. Besides the importance of glycoproteins in biological functions, they are a major component of the fungal cell wall and plasma membrane and contribute to pathogenicity, virulence, and recognition by the host immunity. Given that this structure is absent in host mammalian cells, it stands as an attractive target for developing selective compounds for the treatment of fungal infections. This review focuses on describing the relationship between protein glycosylation and the host–immune interaction in medically relevant fungal species. Full article

(This article belongs to the Section Fungal Pathogenesis and Disease Control)

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17 pages, 2316 KiB

Open AccessArticle

Regulation of Pkc1 Hyper-Phosphorylation by Genotoxic Stress

by Li Liu, Jiri Veis, Wolfgang Reiter, Edwin Motari, Catherine E. Costello, John C. Samuelson, Gustav Ammerer and David E. Levin

J. Fungi 2021, 7(10), 874; https://doi.org/10.3390/jof7100874 - 17 Oct 2021

Cited by 5 | Viewed by 2838

Abstract

The cell wall integrity (CWI) signaling pathway is best known for its roles in cell wall biogenesis. However, it is also thought to participate in the response to genotoxic stress. The stress-activated protein kinase Mpk1 (Slt2, is activated by DNA damaging agents through [...] Read more.

The cell wall integrity (CWI) signaling pathway is best known for its roles in cell wall biogenesis. However, it is also thought to participate in the response to genotoxic stress. The stress-activated protein kinase Mpk1 (Slt2, is activated by DNA damaging agents through an intracellular mechanism that does not involve the activation of upstream components of the CWI pathway. Additional observations suggest that protein kinase C (Pkc1), the top kinase in the CWI signaling cascade, also has a role in the response to genotoxic stress that is independent of its recognized function in the activation of Mpk1. Pkc1 undergoes hyper-phosphorylation specifically in response to genotoxic stress; we have found that this requires the DNA damage checkpoint kinases Mec1 (Mitosis Entry Checkpoint) and Tel1 (TELomere maintenance), but not their effector kinases. We demonstrate that the casein kinase 1 (CK1) ortholog, Hrr25 (HO and Radiation Repair), previously implicated in the DNA damage transcriptional response, associates with Pkc1 under conditions of genotoxic stress. We also found that the induced association of Hrr25 with Pkc1 requires Mec1 and Tel1, and that Hrr25 catalytic activity is required for Pkc1-hyperphosphorylation, thereby delineating a pathway from the checkpoint kinases to Pkc1. We used SILAC mass spectrometry to identify three residues within Pkc1 the phosphorylation of which was stimulated by genotoxic stress. We mutated these residues as well as a collection of 13 phosphorylation sites within the regulatory domain of Pkc1 that fit the consensus for CK1 sites. Mutation of the 13 Pkc1 phosphorylation sites blocked hyper-phosphorylation and diminished RNR3 (RiboNucleotide Reductase) basal expression and induction by genotoxic stress, suggesting that Pkc1 plays a role in the DNA damage transcriptional response. Full article

(This article belongs to the Special Issue The Fungal Cell Wall Integrity Pathway)

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18 pages, 3160 KiB

Open AccessArticle

Characterization of Fungal FAD-Dependent AA3_2 Glucose Oxidoreductases from Hitherto Unexplored Phylogenetic Clades

by Sudarma Dita Wijayanti, Leander Sützl, Adèle Duval and Dietmar Haltrich

J. Fungi 2021, 7(10), 873; https://doi.org/10.3390/jof7100873 - 17 Oct 2021

Cited by 6 | Viewed by 2289

Abstract

The CAZy auxiliary activity family 3 (AA3) comprises FAD-dependent enzymes belonging to the superfamily of glucose-methanol-choline (GMC) oxidoreductases. Glucose oxidase (GOx; EC 1.1.3.4) and glucose dehydrogenase (GDH; EC 1.1.5.9) are part of subfamily AA3_2 and catalyze the oxidation of β-D-glucose at its anomeric [...] Read more.

The CAZy auxiliary activity family 3 (AA3) comprises FAD-dependent enzymes belonging to the superfamily of glucose-methanol-choline (GMC) oxidoreductases. Glucose oxidase (GOx; EC 1.1.3.4) and glucose dehydrogenase (GDH; EC 1.1.5.9) are part of subfamily AA3_2 and catalyze the oxidation of β-D-glucose at its anomeric carbon to D-glucono-1,5-lactone. Recent phylogenetic analysis showed that AA3_2 glucose oxidoreductases can be grouped into four major clades, GOx I and GDH I–III, and in minor clades such as GOx II or distinct subclades. This wide sequence space of AA3_2 glucose oxidoreductases has, however, not been studied in detail, with mainly members of GOx I and GDH I studied biochemically or structurally. Here, we report the biochemical characterization of four fungal glucose oxidoreductases from distinct, hitherto unexplored clades or subclades. The enzyme from Aureobasidium subglaciale, belonging to the minor GOx II clade, showed a typical preference for oxygen and glucose, confirming the correct annotation of this clade. The other three enzymes exhibited strict dehydrogenase activity with different substrate specificities. GDH II from Trichoderma virens showed an almost six-fold higher catalytic efficiency for maltose compared to glucose. The preferred substrate for the two GDH III enzymes from Rhizoctonia solani and Ustilago maydis was gentiobiose, a β(1→6) disaccharide, as judged from the catalytic efficiency. Overall, the newly studied AA3_2 glucose oxidoreductases showed a much broader substrate spectrum than the archetypal GOx from Aspergillus niger, which belongs to clade GOx I. Full article

(This article belongs to the Special Issue Fungal Enzymes 2021)

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11 pages, 885 KiB

Open AccessArticle

Antimycotic Effects of 11 Essential Oil Components and Their Combinations on 13 Food Spoilage Yeasts and Molds

by Laura Nißl, Florian Westhaeuser and Matthias Noll

J. Fungi 2021, 7(10), 872; https://doi.org/10.3390/jof7100872 - 16 Oct 2021

Cited by 2 | Viewed by 1932

Abstract

Food safety is important to reduce food spoilage microorganisms and foodborne pathogens. However, food safety is challenging, as customers’ demand for natural preservatives is increasing. Essential oils (EOs) and their components (EOCs) are alternative antibacterial and antimycotic food additives. In this study, the [...] Read more.

Food safety is important to reduce food spoilage microorganisms and foodborne pathogens. However, food safety is challenging, as customers’ demand for natural preservatives is increasing. Essential oils (EOs) and their components (EOCs) are alternative antibacterial and antimycotic food additives. In this study, the minimal inhibitory concentrations (MIC) of 11 different EOCs against 13 food spoilage molds and yeasts were investigated via the microdilution method. Cinnamaldehyde (CA) revealed the lowest MIC for all tested strains and all EOCs (32.81–328.1 µg ml⁻¹). However, CA is organoleptic and was therefore combined with other EOCs via the checkerboard method. Overall, 27 out of 91 combinations showed a synergistic effect, and both respective EOC concentrations could be reduced by maintaining MIC. Thereby, the combination with citral or citronellal showed promising results. The concentration-dependent effect of CA was studied in further detail on Saccharomyces cerevisiae, with CA causing delayed growth-kinetics and reduced total cell numbers. In addition, flow cytometric measurements combined with live–dead staining indicate the fungicidal effect of CA, due to decreasing total cell numbers and increasing relative amount of propidium iodide-positive cells. In this study, we demonstrated that CA is a potent candidate for the use as a natural preservative against food-relevant mold and yeasts showing fungistatic and fungicidal effects. Therefore, CA and EOC combinations with respective lower EOC concentrations reduce organoleptic reservations, which ease their application in the food industry. Full article

(This article belongs to the Special Issue Different Antimycotoxin Strategies)

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16 pages, 2582 KiB

Open AccessArticle

Bioinformatics and Transcriptome Analysis of CFEM Proteins in Fusarium graminearum

by Lingqiao Chen, Haoyu Wang, Junhua Yang, Xianli Yang, Mengyuan Zhang, Zhihui Zhao, Yingying Fan, Cheng Wang and Jianhua Wang

J. Fungi 2021, 7(10), 871; https://doi.org/10.3390/jof7100871 - 16 Oct 2021

Cited by 8 | Viewed by 2248

Abstract

Fusarium blight of wheat is usually caused by Fusarium graminearum, and the pathogenic fungi will secrete effectors into the host plant tissue to affect its normal physiological process, so as to make it pathogenic. The CFEM (Common in Fungal Extracellular Membrane) protein [...] Read more.

Fusarium blight of wheat is usually caused by Fusarium graminearum, and the pathogenic fungi will secrete effectors into the host plant tissue to affect its normal physiological process, so as to make it pathogenic. The CFEM (Common in Fungal Extracellular Membrane) protein domain is unique to fungi, but it is not found in all fungi. The CFEM protein contained in F. graminearum may be closely related to pathogenicity. In this study, 23 FgCFEM proteins were identified from the F. graminearum genome. Then, features of these proteins, such as signal peptide, subcellular localization, and transmembrane domains, etc., were analyzed and candidate effectors were screened out. Sequence alignment results revealed that each FgCFEM protein contains one CFEM domain. The amino acids of the CFEM domain are highly conserved and contain eight spaced cysteines, with the exception that FgCFEM8, 9, and 15 lack two cysteines and three cysteines were missed in FgCFEM18 and FgCFEM22. A recently identified CFEM_DR motif was detected in 11 FgCFEMs, and importantly we identified two new conserved motifs containing about 29 and 18 amino acids (CFEM_WR and CFEM_KF), respectively, in some of FgCFEM proteins. Transcriptome analysis of the genes encoding CFEM proteins indicated that all the CFEM-containing genes were expressed during wheat infection, with seven and six genes significantly up- and down-regulated, respectively, compared with in planta and in vitro. Based on the above analysis, FgCFEM11 and FgCFEM23 were predicted to be F. graminearum effectors. This study provides the basis for future functional analyses of CFEM proteins in F. graminearum. Full article

(This article belongs to the Special Issue Plant-Pathogenic Fusarium Species)

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20 pages, 9102 KiB

Open AccessArticle

Phytophthora heterospora sp. nov., a New Pseudoconidia-Producing Sister Species of P. palmivora

by Bruno Scanu, Thomas Jung, Hossein Masigol, Benedetto Teodoro Linaldeddu, Marília Horta Jung, Andrea Brandano, Reza Mostowfizadeh-Ghalamfarsa, Josef Janoušek, Mario Riolo and Santa Olga Cacciola

J. Fungi 2021, 7(10), 870; https://doi.org/10.3390/jof7100870 - 16 Oct 2021

Cited by 16 | Viewed by 5741

Abstract

Since 1999, an unusual Phytophthora species has repeatedly been found associated with stem lesions and root and collar rot on young olive trees in Southern Italy. In all cases, this species was obtained from recently established commercial plantations or from nursery plants. Morphologically, [...] Read more.

Since 1999, an unusual Phytophthora species has repeatedly been found associated with stem lesions and root and collar rot on young olive trees in Southern Italy. In all cases, this species was obtained from recently established commercial plantations or from nursery plants. Morphologically, the Phytophthora isolates were characterized by the abundant production of caducous non-papillate conidia-like sporangia (pseudoconidia) and caducous papillate sporangia with a short pedicel, resembling P. palmivora var. heterocystica. Additional isolates with similar features were obtained from nursery plants of Ziziphus spina-christi in Iran, Juniperus oxycedrus and Capparis spinosa in Italy, and mature trees in commercial farms of Durio zibethinus in Vietnam. In this study, morphology, breeding system and growth characteristics of these Phytophthora isolates with peculiar features were examined, and combined mitochondrial and nuclear multigene phylogenetic analyses were performed. The proportion between pseudoconidia and sporangia varied amongst isolates and depended on the availability of free water. Oogonia with amphigynous antheridia and aplerotic oospores were produced in dual cultures with an A2 mating type strain of P. palmivora, indicating all isolates were A1 mating type. Phylogenetically, these isolates grouped in a distinct well-supported clade sister to P. palmivora; thus, they constitute a separate taxon. The new species, described here as Phytophthora heterospora sp. nov., proved to be highly pathogenic to both olive and durian plants in stem inoculation tests. Full article

(This article belongs to the Special Issue Oomycetes – Diversity, Taxonomy, Evolution, Ecology and Host-Pathogen Interactions)

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18 pages, 3105 KiB

Open AccessArticle

The Mycorrizal Status in Vineyards Affected by Esca

by Lucia Landi, Renzo Foglia, Sergio Murolo and Gianfranco Romanazzi

J. Fungi 2021, 7(10), 869; https://doi.org/10.3390/jof7100869 - 16 Oct 2021

Cited by 5 | Viewed by 2136

Abstract

In this work we analyzed the relationship among native arbuscular mycorrhizal fungi (AMF) and vine roots affected by esca, a serious grapevine trunk disease. The AMF symbiosis was analyzed on the roots of neighboring plants (symptomatic and asymptomatic to esca) in 14 sites [...] Read more.

In this work we analyzed the relationship among native arbuscular mycorrhizal fungi (AMF) and vine roots affected by esca, a serious grapevine trunk disease. The AMF symbiosis was analyzed on the roots of neighboring plants (symptomatic and asymptomatic to esca) in 14 sites of three vineyards in Marche region (central–eastern Italy). The AMF colonization intensity, identified by non-vital staining, showed higher value in all esca symptomatic plants (ranging from 24.6% to 61.3%) than neighboring asymptomatic plants (from 17.4% to 57.6%). The same trend of Glomeromycota phylum abundance was detected by analyzing fungal operational taxonomic units (OTUs) linked to the AMF community, obtained by amplicon high throughput analysis of ITS 1 region. Overall, the highest amount of OTUs was detected on roots from symptomatic plants (0.42%), compared to asymptomatic roots (0.29%). Specific primer pairs for native Rhizophagus irregularis and Funneliformis mosseae AMF species, were designed in 28S rRNA and large subunit (LSU) ribosomal RNA, respectively, and droplet digital PCR protocol for absolute quantification was set up. A higher number of DNA copies of both fungal species were detected more frequently in symptomatic than asymptomatic vines. Our study suggests a relationship between esca and native AMF in grapevine. These results underline the importance of native rhizosphere microbial communities for a better knowledge of grapevine esca disease. Full article

(This article belongs to the Special Issue Application of Omics Technologies for a Deeper Insight into the Study of Fungal Trunk Pathogens of Grapevine)

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11 pages, 2541 KiB

Open AccessArticle

Cellulase Enzyme Production from Filamentous Fungi Trichoderma reesei and Aspergillus awamori in Submerged Fermentation with Rice Straw

by Laila Naher, Siti Noor Fatin, Md Abdul Halim Sheikh, Lateef Adebola Azeez, Shaiquzzaman Siddiquee, Norhafizah Md Zain and Sarker Mohammad Rezaul Karim

J. Fungi 2021, 7(10), 868; https://doi.org/10.3390/jof7100868 - 16 Oct 2021

Cited by 14 | Viewed by 4357

Abstract

Fungi are a diverse group of microorganisms that play many roles in human livelihoods. However, the isolation of potential fungal species is the key factor to their utilization in different sectors, including the enzyme industry. Hence, in this study, we used two different [...] Read more.

Fungi are a diverse group of microorganisms that play many roles in human livelihoods. However, the isolation of potential fungal species is the key factor to their utilization in different sectors, including the enzyme industry. Hence, in this study, we used two different fungal repositories—soil and weed leaves—to isolate filamentous fungi and evaluate their potential to produce the cellulase enzyme. The fungal strains were isolated using dichloran rose bengal agar (DRBA) and potato dextrose agar (PDA). For cellulase enzyme production, a rice straw submerged fermentation process was used. The enzyme production was carried out at the different incubation times of 3, 5, and 7 days of culture in submerged conditions with rice straw. Fungal identification studies by morphological and molecular methods showed that the soil colonies matched with Trichoderma reesei, and the weed leaf colonies matched with Aspergillus awamori. These species were coded as T. reesei UMK04 and A. awamori UMK02, respectively. This is the first report of A. awamori UMK02 isolation in Malaysian agriculture. The results of cellulase production using the two fungi incorporated with rice straw submerged fermentation showed that T. reesei produced a higher amount of cellulase at Day 5 (27.04 U/mg of dry weight) as compared with A. awamori (15.19 U/mg of dry weight), and the concentration was significantly different (p < 0.05). Our results imply that T. reesei can be utilized for cellulase production using rice straw. Full article

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18 pages, 2104 KiB

Open AccessArticle

Effect of High-Temperature Stress on Plant Physiological Traits and Mycorrhizal Symbiosis in Maize Plants

by Sonal Mathur, Richa Agnihotri, Mahaveer P. Sharma, Vangimalla R. Reddy and Anjana Jajoo

J. Fungi 2021, 7(10), 867; https://doi.org/10.3390/jof7100867 - 16 Oct 2021

Cited by 10 | Viewed by 2923

Abstract

Increasing high temperature (HT) has a deleterious effect on plant growth. Earlier works reported the protective role of arbuscular mycorrhizal fungi (AMF) under stress conditions, particularly influencing the physiological parameters. However, the protective role of AMF under high-temperature stress examining physiological parameters with [...] Read more.

Increasing high temperature (HT) has a deleterious effect on plant growth. Earlier works reported the protective role of arbuscular mycorrhizal fungi (AMF) under stress conditions, particularly influencing the physiological parameters. However, the protective role of AMF under high-temperature stress examining physiological parameters with characteristic phospholipid fatty acids (PLFA) of soil microbial communities including AMF has not been studied. This work aims to study how high-temperature stress affects photosynthetic and below-ground traits in maize plants with and without AMF. Photosynthetic parameters like quantum yield of photosystem (PS) II, PSI, electron transport, and fractions of open reaction centers decreased in HT exposed plants, but recovered in AMF + HT plants. AMF + HT plants had significantly higher AM-signature 16:1ω5cis neutral lipid fatty acid (NLFA), spore density in soil, and root colonization with lower lipid peroxidation than non-mycorrhizal HT plants. As a result, enriched plants had more active living biomass, which improved photosynthetic efficiency when exposed to heat. This study provides an understanding of how AM-mediated plants can tolerate high temperatures while maintaining the stability of their photosynthetic apparatus. This is the first study to combine above- and below-ground traits, which could lead to a new understanding of plant and rhizosphere stress. Full article

(This article belongs to the Special Issue The Impact of Climate Change on Plant–Fungal Interactions)

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24 pages, 3111 KiB

Open AccessArticle

Waste Rose Flower and Lavender Straw Biomass—An Innovative Lignocellulose Feedstock for Mycelium Bio-Materials Development Using Newly Isolated Ganoderma resinaceum GA1M

by Galena Angelova, Mariya Brazkova, Petya Stefanova, Denica Blazheva, Veselin Vladev, Nadejda Petkova, Anton Slavov, Petko Denev, Daniela Karashanova, Roumiana Zaharieva, Atanas Enev and Albert Krastanov

J. Fungi 2021, 7(10), 866; https://doi.org/10.3390/jof7100866 - 15 Oct 2021

Cited by 15 | Viewed by 3287

Abstract

In this study, for the first time, the potential of rose flowers and lavender straw waste biomass was studied as feeding lignocellulose substrates for the cultivation of newly isolated in Bulgaria Ganoderma resinaceum GA1M with the objective of obtaining mycelium-based bio [...] Read more.

In this study, for the first time, the potential of rose flowers and lavender straw waste biomass was studied as feeding lignocellulose substrates for the cultivation of newly isolated in Bulgaria Ganoderma resinaceum GA1M with the objective of obtaining mycelium-based bio-composites. The chemical characterization and Fourier Transform Infrared (FTIR) spectroscopy established that the proximate composition of steam distilled lavender straw (SDLS) and hexane extracted rose flowers (HERF) was a serious prerequisite supporting the self-growth of mycelium bio-materials with improved antibacterial and aromatic properties. The basic physico-mechanical properties of the developed bio-composites were determined. The apparent density of the mycelium HERF-based bio-composites (462 kg/m³) was higher than that of the SDLS-based bio-composite (347 kg/m³) and both were much denser than expanded polystyren (EPS), lighter than medium-density fiber board (MDF) and oriented strand board (OSB) and similar to hempcrete. The preliminary testing of their compressive behavior revealed that the compressive resistance of SDLS-based bio-composite was 718 kPa, while for HERF-based bio-composite it was 1029 kPa and both values are similar to the compressive strength of hempcrete with similar apparent density. Water absorbance analysis showed, that both mycelium HERF- and SDLS-based bio-composites were hydrophilic and further investigations are needed to limit the hydrophilicity of the lignocellulose fibers, to tune the density and to improve compressive resistance. Full article

(This article belongs to the Special Issue Fungal Biotechnology and Application)

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12 pages, 824 KiB

Open AccessArticle

Genomic Diversity Analysis Reveals a Strong Population Structure in Histoplasma capsulatum LAmA (Histoplasma suramericanum)

by Fernando Almeida-Silva, Marcus de Melo Teixeira, Daniel R. Matute, Marcela de Faria Ferreira, Bridget M. Barker, Rodrigo Almeida-Paes, Allan J. Guimarães and Rosely M. Zancopé-Oliveira

J. Fungi 2021, 7(10), 865; https://doi.org/10.3390/jof7100865 - 15 Oct 2021

Cited by 8 | Viewed by 1859

Abstract

Histoplasmosis is a severe mycotic disease affecting thousands of immunocompetent and immunocompromised individuals with high incidence in Latin America, where the disease agents are Histoplasma capsulatum and Histoplasma suramericanum. In this work, we used whole-genome sequencing to infer the species diversity and [...] Read more.

Histoplasmosis is a severe mycotic disease affecting thousands of immunocompetent and immunocompromised individuals with high incidence in Latin America, where the disease agents are Histoplasma capsulatum and Histoplasma suramericanum. In this work, we used whole-genome sequencing to infer the species diversity and the population structure of H. suramericanum in South America. We find evidence for strong population structure and little admixture within the species. Genome-level phylogenetic trees indicate the existence of at least three different discrete populations. We recovered the existence of a previously identified population, LAmB, and confirm that it is highly differentiated along the whole genome. We also find that H. suramericanum is composed of two populations, one in Northern South America, and another in the southern portion of the continent. Moreover, one of the lineages from the southern population is endemic to Rio de Janeiro and there was no association with clinical data and species isolated from patients with histoplasmosis. Our results point out the need to characterize the symptomatology of histoplasmosis caused by different species and lineages of Histoplasma spp. Full article

(This article belongs to the Special Issue Omics and Systems Biology of Fungal Diseases)

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25 pages, 5632 KiB

Open AccessArticle

Genome Comparisons of the Fission Yeasts Reveal Ancient Collinear Loci Maintained by Natural Selection

by Lajos Acs-Szabo, Laszlo Attila Papp, Matthias Sipiczki and Ida Miklos

J. Fungi 2021, 7(10), 864; https://doi.org/10.3390/jof7100864 - 14 Oct 2021

Cited by 1 | Viewed by 1872

Abstract

Fission yeasts have a unique life history and exhibit distinct evolutionary patterns from other yeasts. Besides, the species demonstrate stable genome structures despite the relatively fast evolution of their genomic sequences. To reveal what could be the reason for that, comparative genomic analyses [...] Read more.

Fission yeasts have a unique life history and exhibit distinct evolutionary patterns from other yeasts. Besides, the species demonstrate stable genome structures despite the relatively fast evolution of their genomic sequences. To reveal what could be the reason for that, comparative genomic analyses were carried out. Our results provided evidence that the structural and sequence evolution of the fission yeasts were correlated. Moreover, we revealed ancestral locally collinear blocks (aLCBs), which could have been inherited from their last common ancestor. These aLCBs proved to be the most conserved regions of the genomes as the aLCBs contain almost eight genes/blocks on average in the same orientation and order across the species. Gene order of the aLCBs is mainly fission-yeast-specific but supports the idea of filamentous ancestors. Nevertheless, the sequences and gene structures within the aLCBs are as mutable as any sequences in other parts of the genomes. Although genes of certain Gene Ontology (GO) categories tend to cluster at the aLCBs, those GO enrichments are not related to biological functions or high co-expression rates, they are, rather, determined by the density of essential genes and Rec12 cleavage sites. These data and our simulations indicated that aLCBs might not only be remnants of ancestral gene order but are also maintained by natural selection. Full article

(This article belongs to the Special Issue Yeast Genetics 2021)

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22 pages, 4425 KiB

Open AccessArticle

Quantifying the Role of Ground Beetles for the Dispersal of Fusarium and Alternaria Fungi in Agricultural Landscapes

by Nadja Heitmann, Michael Glemnitz, Peter Lentzsch, Ralph Platen and Marina E. H. Müller

J. Fungi 2021, 7(10), 863; https://doi.org/10.3390/jof7100863 - 14 Oct 2021

Cited by 9 | Viewed by 1794

Abstract

The spread by arthropods (zoochory) is an essential dispersal mechanism for many microorganisms, like plant pathogens. Carabid beetles are very abundant and mobile ground-dwelling insects. However, their role in the dispersal of economically relevant phytopathogens, like Fusarium and Alternaria fungi is basically unknown. [...] Read more.

The spread by arthropods (zoochory) is an essential dispersal mechanism for many microorganisms, like plant pathogens. Carabid beetles are very abundant and mobile ground-dwelling insects. However, their role in the dispersal of economically relevant phytopathogens, like Fusarium and Alternaria fungi is basically unknown. We quantified the total fungal, Fusarium, and Alternaria load of carabid species collected in the transition zones between small water bodies and wheat fields by screening (i) their body surface for fungal propagules with a culture-dependent method and (ii) their entire bodies for fungal DNA with a qPCR approach. The analysis of entire bodies detects fungal DNA in all carabid beetles but Alternaria DNA in 98% of them. We found that 74% of the carabids carried fungal propagules on the body surface, of which only half (49%) carried Fusarium propagules. We identified eight Fusarium and four Alternaria species on the body surface; F. culmorum was dominant. The fungal, Fusarium and Alternaria, load differed significantly between the carabid species and was positively affected by the body size and weight of the carabids. Carabid beetles reveal a remarkable potential to disseminate different fungi. Dispersal by ground-dwelling arthropods could affect the spatial-temporal patterns of plant disease and microorganisms in general. Full article

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26 pages, 3400 KiB

Open AccessArticle

Strain Degeneration in Pleurotus ostreatus: A Genotype Dependent Oxidative Stress Process Which Triggers Oxidative Stress, Cellular Detoxifying and Cell Wall Reshaping Genes

by Gumer Pérez, Federico Lopez-Moya, Emilia Chuina, María Ibañez-Vea, Edurne Garde, Luis V. López-Llorca, Antonio G. Pisabarro and Lucía Ramírez

J. Fungi 2021, 7(10), 862; https://doi.org/10.3390/jof7100862 - 14 Oct 2021

Cited by 12 | Viewed by 3137

Abstract

Strain degeneration has been defined as a decrease or loss in the yield of important commercial traits resulting from subsequent culture, which ultimately leads to Reactive Oxygen Species (ROS) production. Pleurotus ostreatus is a lignin-producing nematophagous edible mushroom. Mycelia for mushroom production are [...] Read more.

Strain degeneration has been defined as a decrease or loss in the yield of important commercial traits resulting from subsequent culture, which ultimately leads to Reactive Oxygen Species (ROS) production. Pleurotus ostreatus is a lignin-producing nematophagous edible mushroom. Mycelia for mushroom production are usually maintained in subsequent culture in solid media and frequently show symptoms of strain degeneration. The dikaryotic strain P. ostreatus (DkN001) has been used in our lab as a model organism for different purposes. Hence, different tools have been developed to uncover genetic and molecular aspects of this fungus. In this work, strain degeneration was studied in a full-sib monokaryotic progeny of the DkN001 strain with fast (F) and slow (S) growth rates by using different experimental approaches (light microscopy, malondialdehyde levels, whole-genome transcriptome analysis, and chitosan effect on monokaryotic mycelia). The results obtained showed that: (i) strain degeneration in P. ostreatus is linked to oxidative stress, (ii) the oxidative stress response in monokaryons is genotype dependent, (iii) stress and detoxifying genes are highly expressed in S monokaryons with symptoms of strain degeneration, (iv) chitosan addition to F and S monokaryons uncovered the constitutive expression of both oxidative stress and cellular detoxifying genes in S monokaryon strains which suggest their adaptation to oxidative stress, and (v) the overexpression of the cell wall genes, Uap1 and Cda1, in S monokaryons with strain degeneration phenotype indicates cell wall reshaping and the activation of High Osmolarity Glycerol (HOG) and Cell Wall Integrity (CWI) pathways. These results could constitute a hallmark for mushroom producers to distinguish strain degeneration in commercial mushrooms. Full article

(This article belongs to the Special Issue Genetics and Breeding of Basidiomycetes for Biotechnology)

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18 pages, 4753 KiB

Open AccessArticle

A New Double-Stranded RNA Mycovirus in Cryphonectria naterciae Is Able to Cross the Species Barrier and Is Deleterious to a New Host

by Carolina Cornejo, Sakae Hisano, Helena Bragança, Nobuhiro Suzuki and Daniel Rigling

J. Fungi 2021, 7(10), 861; https://doi.org/10.3390/jof7100861 - 14 Oct 2021

Cited by 16 | Viewed by 2553

Abstract

Cryphonectria is a fungal genus associated with economically significant disease of trees. Herein we characterized a novel double-stranded RNA virus from the fungal species Cryphonectria naterciae, a species unexplored as a virus host. De novo assembly of RNA-seq data and Sanger sequencing [...] Read more.

Cryphonectria is a fungal genus associated with economically significant disease of trees. Herein we characterized a novel double-stranded RNA virus from the fungal species Cryphonectria naterciae, a species unexplored as a virus host. De novo assembly of RNA-seq data and Sanger sequencing of RACE (rapid amplification of cDNA ends) clones gave the complete, non-segmented genome (10,164 bp) of the virus termed Cryphonectria naterciae fusagravirus (CnFGV1) that was phylogenetically placed within the previously proposed viral family Fusagraviridae. Of 31 field-collected strains of C. naterciae, 40% tested CnFGV1-positive. Cocultivation resulted in within-species transmission of CnFGV1 to virus-free strains of C. naterciae. Comparison of the mycelium phenotype and the growth rate of CnFGV1-infected and virus-free isogenic strains revealed frequent sectoring and growth reduction in C. naterciae upon virus infection. Co-culturing also led to cross-species transmission of CnFGV1 to Cryphonectria carpinicola and Cryphonectria radicalis, but not to Cryphonectria parasitica. The virus-infected C. naterciae and the experimentally infected Cryphonectria spp. readily transmitted CnFGV1 through asexual spores to the next generation. CnFGV1 strongly reduced conidiation and in some cases vegetative growth of C. carpinicola, which is involved in the European hornbeam disease. This study is the first report of a fusagravirus in the family Cryphonectriaceae and lays the groundwork for assessing a hypovirulence effect of CnFGV1 against the hornbeam decline in Europe. Full article

(This article belongs to the Special Issue Toxins of Fusarium and Mycoviruses)

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25 pages, 20285 KiB

Open AccessArticle

Genetic Analyses of Amphotericin B Susceptibility in Aspergillus fumigatus

by Yuying Fan, Gregory A. Korfanty and Jianping Xu

J. Fungi 2021, 7(10), 860; https://doi.org/10.3390/jof7100860 - 14 Oct 2021

Cited by 5 | Viewed by 1933

Abstract

Aspergillus fumigatus is a ubiquitous saprophytic mold that can cause a range of clinical syndromes, from allergic reactions to invasive infections. Amphotericin B (AMB) is a polyene antifungal drug that has been used to treat a broad range of systemic mycoses since 1958, [...] Read more.

Aspergillus fumigatus is a ubiquitous saprophytic mold that can cause a range of clinical syndromes, from allergic reactions to invasive infections. Amphotericin B (AMB) is a polyene antifungal drug that has been used to treat a broad range of systemic mycoses since 1958, including as a primary treatment option against invasive aspergillosis in regions with high rates (≥10%) of environmental triazole resistance. However, cases of AMB-resistant A. fumigatus strains have been increasingly documented over the years, and high resistance rates were recently reported in Brazil and Canada. The objective of this study is to identify candidate mutations associated with AMB susceptibility using a genome-wide association analysis of natural strains, and to further investigate a subset of the mutations in their putative associations with differences in AMB minimum inhibitory concentration (MIC) and in growths at different AMB concentrations through the analysis of progeny from a laboratory genetic cross. Together, our results identified a total of 34 candidate single-nucleotide polymorphisms (SNPs) associated with AMB MIC differences—comprising 18 intergenic variants, 14 missense variants, one synonymous variant, and one non-coding transcript variant. Importantly, progeny from the genetic cross allowed us to identify putative SNP–SNP interactions impacting progeny growth at different AMB concentrations. Full article

(This article belongs to the Special Issue Fungal Infections: From Diagnostics to Treatments)

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15 pages, 1292 KiB

Open AccessArticle

Fungal Biomarkers Stability in Mars Regolith Analogues after Simulated Space and Mars-like Conditions

by Alessia Cassaro, Claudia Pacelli, Mickael Baqué, Jean-Pierre Paul de Vera, Ute Böttger, Lorenzo Botta, Raffaele Saladino, Elke Rabbow and Silvano Onofri

J. Fungi 2021, 7(10), 859; https://doi.org/10.3390/jof7100859 - 14 Oct 2021

Cited by 6 | Viewed by 2075

Abstract

The discovery of life on other planets and moons in our solar system is one of the most important challenges of this era. The second ExoMars mission will look for traces of extant or extinct life on Mars. The instruments on board the [...] Read more.

The discovery of life on other planets and moons in our solar system is one of the most important challenges of this era. The second ExoMars mission will look for traces of extant or extinct life on Mars. The instruments on board the rover will be able to reach samples with eventual biomarkers until 2 m of depth under the planet’s surface. This exploration capacity offers the best chance to detect biomarkers which would be mainly preserved compared to samples on the surface which are directly exposed to harmful environmental conditions. Starting with the studies of the endolithic meristematic black fungus Cryomyces antarcticus, which has proved its high resistance under extreme conditions, we analyzed the stability and the resistance of fungal biomarkers after exposure to simulated space and Mars-like conditions, with Raman and Gas Chromatography–Mass Spectrometry, two of the scientific payload instruments on board the rover. Full article

(This article belongs to the Special Issue Fungal Pigments 2021)

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16 pages, 4289 KiB

Open AccessArticle

MAT Loci Play Crucial Roles in Sexual Development but Are Dispensable for Asexual Reproduction and Pathogenicity in Rice Blast Fungus Magnaporthe oryzae

by Jiao-yu Wang, Shi-zhen Wang, Zhen Zhang, Zhong-na Hao, Xiao-xiao Shi, Ling Li, Xue-ming Zhu, Hai-ping Qiu, Rong-yao Chai, Yan-li Wang, Lin Li, Xiao-hong Liu, Xiao-xiao Feng, Guo-chang Sun and Fu-cheng Lin

J. Fungi 2021, 7(10), 858; https://doi.org/10.3390/jof7100858 - 13 Oct 2021

Cited by 3 | Viewed by 1911

Abstract

Magnaporthe oryzae, a fungal pathogen that causes rice blast, which is the most destructive disease of rice worldwide, has the potential to perform both asexual and sexual reproduction. MAT loci, consisting of MAT genes, were deemed to determine the mating types of [...] Read more.

Magnaporthe oryzae, a fungal pathogen that causes rice blast, which is the most destructive disease of rice worldwide, has the potential to perform both asexual and sexual reproduction. MAT loci, consisting of MAT genes, were deemed to determine the mating types of M. oryzae strains. However, investigation was rarely performed on the development and molecular mechanisms of the sexual reproduction of the fungus. In the present work, we analyzed the roles of two MAT loci and five individual MAT genes in the sex determination, sexual development and pathogenicity of M. oryzae. Both of the MAT1-1 and MAT1-2 loci are required for sex determination and the development of sexual structures. MAT1-1-1, MAT1-1-3 and MAT1-2-1 genes are crucial for the formation of perithecium. MAT1-1-2 impacts the generation of asci and ascospores, while MAT1-2-2 is dispensable for sexual development. A GFP fusion experiment indicated that the protein of MAT1-1-3 is distributed in the nucleus. However, all of the MAT loci or MAT genes are dispensable for vegetative growth, asexual reproduction, pathogenicity and pathogenicity-related developments of the fungus, suggesting that sexual reproduction is regulated relatively independently in the development of the fungus. The data and methods of this work may be helpful to further understand the life cycle and the variation of the fungus. Full article

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25 pages, 23979 KiB

Open AccessArticle

Species Diversity and Distribution Characteristics of Calonectria in Five Soil Layers in a Eucalyptus Plantation

by LingLing Liu, WenXia Wu and ShuaiFei Chen

J. Fungi 2021, 7(10), 857; https://doi.org/10.3390/jof7100857 - 13 Oct 2021

Cited by 17 | Viewed by 2165

Abstract

The genus Calonectria includes pathogens of various agricultural, horticultural, and forestry crops. Species of Calonectria are commonly collected from soils, fruits, leaves, stems, and roots. Some species of Calonectria isolated from soils are considered as important plant pathogens. Understanding the species diversity and [...] Read more.

The genus Calonectria includes pathogens of various agricultural, horticultural, and forestry crops. Species of Calonectria are commonly collected from soils, fruits, leaves, stems, and roots. Some species of Calonectria isolated from soils are considered as important plant pathogens. Understanding the species diversity and distribution characteristics of Calonectria species in different soil layers will help us to clarify their long-term potential harm to plants and their patterns of dissemination. To our knowledge, no systematic research has been conducted concerning the species diversity and distribution characteristics of Calonectria in different soil layers. In this study, 1000 soil samples were collected from five soil layers (0–20, 20–40, 40–60, 60–80, and 80–100 cm) at 100 sampling points in one 15-year-old Eucalyptus urophylla hybrid plantation in southern China. A total of 1037 isolates of Calonectria present in all five soil layers were obtained from 93 of 100 sampling points. The 1037 isolates were identified based on DNA sequence comparisons of the translation elongation factor 1-alpha (tef1), β-tubulin (tub2), calmodulin (cmdA), and histone H3 (his3) gene regions, as well as the combination of morphological characteristics. These isolates were identified as C. hongkongensis (665 isolates; 64.1%), C. aconidialis (250 isolates; 24.1%), C. kyotensis (58 isolates; 5.6%), C. ilicicola (47 isolates; 4.5%), C. chinensis (2 isolates; 0.2%), and C. orientalis (15 isolates; 1.5%). With the exception of C. orientalis, which resides in the C. brassicae species complex, the other five species belonged to the C. kyotensis species complex. The results showed that the number of sampling points that yielded Calonectria and the number (and percentage) of Calonectria isolates obtained decreased with increasing depth of the soil. More than 84% of the isolates were obtained from the 0–20 and 20–40 cm soil layers. The deeper soil layers had comparatively lower numbers but still harbored a considerable number of Calonectria. The diversity of five species in the C. kyotensis species complex decreased with increasing soil depth. The genotypes of isolates in each Calonectria species were determined by tef1 and tub2 gene sequences. For each species in the C. kyotensis species complex, in most cases, the number of genotypes decreased with increasing soil depth. The 0–20 cm soil layer contained all of the genotypes of each species. To our knowledge, this study presents the first report of C. orientalis isolated in China. This species was isolated from the 40–60 and 60–80 cm soil layers at only one sampling point, and only one genotype was present. This study has enhanced our understanding of the species diversity and distribution characteristics of Calonectria in different soil layers. Full article

(This article belongs to the Special Issue Biodiversity, Distribution and Conservation of Plants and Fungi; Effects of Global Warming and Environmental Stress)

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15 pages, 342 KiB

Open AccessReview

Update on Dihydropteroate Synthase (DHPS) Mutations in Pneumocystis jirovecii

by Carmen de la Horra, Vicente Friaza, Rubén Morilla, Juan Delgado, Francisco J. Medrano, Robert F. Miller, Yaxsier de Armas and Enrique J. Calderón

J. Fungi 2021, 7(10), 856; https://doi.org/10.3390/jof7100856 - 13 Oct 2021

Cited by 11 | Viewed by 2247

Abstract

A Pneumocystis jirovecii is one of the most important microorganisms that cause pneumonia in immunosupressed individuals. The guideline for treatment and prophylaxis of Pneumocystis pneumonia (PcP) is the use of a combination of sulfa drug-containing trimethroprim and sulfamethoxazole. In the absence of a [...] Read more.

A Pneumocystis jirovecii is one of the most important microorganisms that cause pneumonia in immunosupressed individuals. The guideline for treatment and prophylaxis of Pneumocystis pneumonia (PcP) is the use of a combination of sulfa drug-containing trimethroprim and sulfamethoxazole. In the absence of a reliable method to culture Pneumocystis, molecular techniques have been developed to detect mutations in the dihydropteroate synthase gene, the target of sulfa drugs, where mutations are related to sulfa resistance in other microorganisms. The presence of dihydropteroate synthase (DHPS) mutations has been described at codon 55 and 57 and found almost around the world. In the current work, we analyzed the most common methods to identify these mutations, their geographical distribution around the world, and their clinical implications. In addition, we describe new emerging DHPS mutations. Other aspects, such as the possibility of transmitting Pneumocystis mutated organisms between susceptible patients is also described, as well as a brief summary of approaches to study these mutations in a heterologous expression system. Full article

(This article belongs to the Special Issue Advances in Pneumocystis Infection)

18 pages, 947 KiB

Open AccessReview

Chronic Diseases Associated with Malassezia Yeast

by Abdourahim Abdillah and Stéphane Ranque

J. Fungi 2021, 7(10), 855; https://doi.org/10.3390/jof7100855 - 12 Oct 2021

Cited by 14 | Viewed by 5008

Abstract

Malassezia are a lipid-dependent basidiomycetous yeast of the normal skin microbiome, although Malassezia DNA has been recently detected in other body sites and has been associated with certain chronic human diseases. This new perspective raises many questions. Are these yeasts truly present in [...] Read more.

Malassezia are a lipid-dependent basidiomycetous yeast of the normal skin microbiome, although Malassezia DNA has been recently detected in other body sites and has been associated with certain chronic human diseases. This new perspective raises many questions. Are these yeasts truly present in the investigated body site or were they contaminated by other body sites, adjacent or not? Does this DNA contamination come from living or dead yeast? If these yeasts are alive, do they belong to the resident mycobiota or are they transient colonizers which are not permanently established within these niches? Finally, are these yeasts associated with certain chronic diseases or not? In an attempt to shed light on this knowledge gap, we critically reviewed the 31 published studies focusing on the association of Malassezia spp. with chronic human diseases, including psoriasis, atopic dermatitis (AD), chronic rhinosinusitis (CRS), asthma, cystic fibrosis (CF), HIV infection, inflammatory bowel disease (IBD), colorectal cancer (CRC), and neurodegenerative diseases. Full article

(This article belongs to the Topic Novel Concepts and Approaches in Neglected, Emerging and Re-Emerging Pathogens: From Environment to Patient)

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J. Fungi, Volume 7, Issue 10 (October 2021) – 100 articles

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