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Virulence Apr 2017Many species of fungi have been detected in the healthy human gut; however, nearly half of all taxa reported have only been found in one sample or one study. Fungi... (Review)
Review
Many species of fungi have been detected in the healthy human gut; however, nearly half of all taxa reported have only been found in one sample or one study. Fungi capable of growing in and colonizing the gut are limited to a small number of species, mostly Candida yeasts and yeasts in the family Dipodascaceae (Galactomyces, Geotrichum, Saprochaete). Malassezia and the filamentous fungus Cladosporium are potential colonizers; more work is needed to clarify their role. Other commonly-detected fungi come from the diet or environment but either cannot or do not colonize (Penicillium and Debaryomyces species, which are common on fermented foods but cannot grow at human body temperature), while still others have dietary or environmental sources (Saccharomyces cerevisiae, a fermentation agent and sometime probiotic; Aspergillus species, ubiquitous molds) yet are likely to impact gut ecology. The gut mycobiome appears less stable than the bacterial microbiome, and is likely subject to environmental factors.
Topics: Diet; Environmental Exposure; Fungi; Gastrointestinal Microbiome; Gastrointestinal Tract; Humans; Microbiota; Mycobiome
PubMed: 27736307
DOI: 10.1080/21505594.2016.1247140 -
Microbiology Spectrum Nov 2016Many Fungi have a well-developed secondary metabolism. The diversity of fungal species and the diversification of biosynthetic gene clusters underscores a nearly... (Review)
Review
Many Fungi have a well-developed secondary metabolism. The diversity of fungal species and the diversification of biosynthetic gene clusters underscores a nearly limitless potential for metabolic variation and an untapped resource for drug discovery and synthetic biology. Much of the ecological success of the filamentous fungi in colonizing the planet is owed to their ability to deploy their secondary metabolites in concert with their penetrative and absorptive mode of life. Fungal secondary metabolites exhibit biological activities that have been developed into life-saving medicines and agrochemicals. Toxic metabolites, known as mycotoxins, contaminate human and livestock food and indoor environments. Secondary metabolites are determinants of fungal diseases of humans, animals, and plants. Secondary metabolites exhibit a staggering variation in chemical structures and biological activities, yet their biosynthetic pathways share a number of key characteristics. The genes encoding cooperative steps of a biosynthetic pathway tend to be located contiguously on the chromosome in coregulated gene clusters. Advances in genome sequencing, computational tools, and analytical chemistry are enabling the rapid connection of gene clusters with their metabolic products. At least three fungal drug precursors, penicillin K and V, mycophenolic acid, and pleuromutilin, have been produced by synthetic reconstruction and expression of respective gene clusters in heterologous hosts. This review summarizes general aspects of fungal secondary metabolism and recent developments in our understanding of how and why fungi make secondary metabolites, how these molecules are produced, and how their biosynthetic genes are distributed across the Fungi. The breadth of fungal secondary metabolite diversity is highlighted by recent information on the biosynthesis of important fungus-derived metabolites that have contributed to human health and agriculture and that have negatively impacted crops, food distribution, and human environments.
Topics: Biosynthetic Pathways; Diterpenes; Fungi; Genome, Fungal; Humans; Mycophenolic Acid; Mycotoxins; Polycyclic Compounds; Secondary Metabolism; Synthetic Biology; Pleuromutilins
PubMed: 27809954
DOI: 10.1128/microbiolspec.FUNK-0009-2016 -
Seminars in Respiratory and Critical... Feb 2024The filamentous fungus causes a wide spectrum of diseases in the human lung, with being the most pathogenic and allergenic subspecies. The broad range of clinical... (Review)
Review
The filamentous fungus causes a wide spectrum of diseases in the human lung, with being the most pathogenic and allergenic subspecies. The broad range of clinical syndromes that can develop from the presence of in the respiratory tract is determined by the interaction between host and pathogen. In this review, an oversight of the different clinical entities of pulmonary aspergillosis is given, categorized by their main pathophysiological mechanisms. The underlying immune processes are discussed, and the main clinical, radiological, biochemical, microbiological, and histopathological findings are summarized.
Topics: Humans; Lung; Aspergillus; Pulmonary Aspergillosis; Aspergillus fumigatus
PubMed: 38286136
DOI: 10.1055/s-0043-1777259 -
The New Phytologist Jun 2022Lichens are the symbiotic outcomes of open, interspecies relationships, central to which are a fungus and a phototroph, typically an alga and/or cyanobacterium. The... (Review)
Review
Lichens are the symbiotic outcomes of open, interspecies relationships, central to which are a fungus and a phototroph, typically an alga and/or cyanobacterium. The evolutionary processes that led to the global success of lichens are poorly understood. In this review, we explore the goods and services exchange between fungus and phototroph and how this propelled the success of both symbiont and symbiosis. Lichen fungal symbionts count among the only filamentous fungi that expose most of their mycelium to an aerial environment. Phototrophs export carbohydrates to the fungus, which converts them to specific polyols. Experimental evidence suggests that polyols are not only growth and respiratory substrates but also play a role in anhydrobiosis, the capacity to survive desiccation. We propose that this dual functionality is pivotal to the evolution of fungal symbionts, enabling persistence in environments otherwise hostile to fungi while simultaneously imposing costs on growth. Phototrophs, in turn, benefit from fungal protection from herbivory and light stress, while appearing to exert leverage over fungal sex and morphogenesis. Combined with the recently recognized habit of symbionts to occur in multiple symbioses, this creates the conditions for a multiplayer marketplace of rewards and penalties that could drive symbiont selection and lichen diversification.
Topics: Biology; Cyanobacteria; Fungi; Lichens; Phylogeny; Symbiosis
PubMed: 35302240
DOI: 10.1111/nph.18048 -
Microbiology Spectrum Aug 2022Biofilms are protective structures for pathogens of plants and animals, in which cells are shielded from host defense responses and antimicrobial treatments. Although...
Biofilms are protective structures for pathogens of plants and animals, in which cells are shielded from host defense responses and antimicrobial treatments. Although biofilms are well studied in bacterial pathogens, their development and structure in filamentous fungi, as well as their role in pathogenicity, are poorly understood. We show that the economically important plant pathogen Fusarium graminearum, a filamentous fungus, forms biofilms which adhere to polystyrene, a hydrophobic surface. The biofilms have complex hyphal structures surrounded by a polymeric matrix that consists primarily of polysaccharides and extracellular nucleic acids, and lack lipids. Pellicles are formed in liquid cultures, floating biofilm masses that are common in bacterial biofilms, and noted but undescribed in filamentous fungal biofilms. Commonly, F. graminearum grows as hyphal colonies; however, on media which lack electron acceptors, an altered morphology is formed with predominantly short, bulbous hyphae embedded in the matrix. Supplementation of the biofilm-inducing medium with an electron acceptor restores the filamentous hyphal morphology, demonstrating that the formation of bulbous hyphae is due, at least in part, to oxidative stress. Plant hosts infected with pathogens generally respond by producing reactive oxygen species, commonly produced as a defense response. Thus, the formation of biofilms strongly suggests a role in protecting cells from host responses during the course of plant disease. Fusarium graminearum is a filamentous fungal pathogen that causes Fusarium head blight (FHB) in cereal crops, leading to devastating crop losses. We have demonstrated the ability of this pathogen to form biofilms. Biofilms are likely to be important in the disease cycle of F. graminearum and other plant pathogens, protecting cells from plant defenses and environmental conditions. Towards this end, we have characterized the formation of biofilms in F. graminearum , which, together with ongoing characterization of their association with host plants, provides a basis for understanding the functionality of biofilms in the pathogen disease cycle.
Topics: Biofilms; Fusarium; Hyphae; Plant Diseases
PubMed: 35950855
DOI: 10.1128/spectrum.00171-22 -
Current Genetics May 2016The infection cycle of filamentous fungi consists of two main stages: invasion (growth) and dispersion (development). After the deposition of a spore on a host,... (Review)
Review
The infection cycle of filamentous fungi consists of two main stages: invasion (growth) and dispersion (development). After the deposition of a spore on a host, germination, polar extension and branching of vegetative cells called hyphae allow a fast and efficient invasion. Under suboptimal conditions, genetic reprogramming of hyphae results in the generation of asexual spores, allowing dissemination to new hosts and the beginning of a new infection cycle. In the model filamentous fungus Aspergillus nidulans, asexual development or conidiation is induced by the upstream developmental activation (UDA) pathway. UDA proteins transduce signals from the tip, the polarity site of hyphae, to nuclei, where developmental programs are transcriptionally activated. The present review summarizes the current knowledge on this tip-to-nucleus communication mechanism, emphasizing its dependence on hyphal polarity. Future approaches to the topic will also be suggested, as stimulating elements contributing to the understanding of how apical signals are coupled with the transcriptional control of development and pathogenesis in filamentous fungi.
Topics: Animals; Aspergillus nidulans; Cell Nucleus; Hyphae; Life Cycle Stages
PubMed: 26782172
DOI: 10.1007/s00294-015-0556-0 -
Microbiology Spectrum Apr 2017Filamentous fungi are a large and ancient clade of microorganisms that occupy a broad range of ecological niches. The success of filamentous fungi is largely due to... (Review)
Review
Filamentous fungi are a large and ancient clade of microorganisms that occupy a broad range of ecological niches. The success of filamentous fungi is largely due to their elongate hypha, a chain of cells, separated from each other by septa. Hyphae grow by polarized exocytosis at the apex, which allows the fungus to overcome long distances and invade many substrates, including soils and host tissues. Hyphal tip growth is initiated by establishment of a growth site and the subsequent maintenance of the growth axis, with transport of growth supplies, including membranes and proteins, delivered by motors along the cytoskeleton to the hyphal apex. Among the enzymes delivered are cell wall synthases that are exocytosed for local synthesis of the extracellular cell wall. Exocytosis is opposed by endocytic uptake of soluble and membrane-bound material into the cell. The first intracellular compartment in the endocytic pathway is the early endosomes, which emerge to perform essential additional functions as spatial organizers of the hyphal cell. Individual compartments within septated hyphae can communicate with each other via septal pores, which allow passage of cytoplasm or organelles to help differentiation within the mycelium. This article introduces the reader to more detailed aspects of hyphal growth in fungi.
Topics: Fungal Proteins; Fungi; Hyphae
PubMed: 28429675
DOI: 10.1128/microbiolspec.FUNK-0034-2016 -
Scientific Reports Nov 2022We report the utilization of Third-Harmonic Generation microscopy for label-free live cell imaging of lipid droplets in the hypha of filamentous fungus Phycomyces...
We report the utilization of Third-Harmonic Generation microscopy for label-free live cell imaging of lipid droplets in the hypha of filamentous fungus Phycomyces blakesleeanus. THG microscopy images showed bright spherical features dispersed throughout the hypha cytoplasm in control conditions and a transient increase in the number of bright features after complete nitrogen starvation. Colocalization analysis of THG and lipid-counterstained images disclosed that the cytoplasmic particles were lipid droplets. Particle Size Analysis and Image Correlation Spectroscopy were used to quantify the number density and size of lipid droplets. The two analysis methods both revealed an increase from 16 × 10 to 23 × 10 lipid droplets/µm after nitrogen starvation and a decrease in the average size of the droplets (range: 0.5-0.8 µm diameter). In conclusion, THG imaging, followed by PSA and ICS, can be reliably used for filamentous fungi for the in vivo quantification of lipid droplets without the need for labeling and/or fixation. In addition, it has been demonstrated that ICS is suitable for THG microscopy.
Topics: Lipid Droplets; Second Harmonic Generation Microscopy; Microscopy; Fungi; Nitrogen
PubMed: 36335164
DOI: 10.1038/s41598-022-23502-4 -
Molecules (Basel, Switzerland) Nov 2020, a common saprobic filamentous fungus, not only plays an important role in biological control, but also has applications in medicine, food, and environmental... (Review)
Review
, a common saprobic filamentous fungus, not only plays an important role in biological control, but also has applications in medicine, food, and environmental protection. In this paper, 223 secondary metabolites and their bioactivities from 13 known species and various unidentified strains of are reviewed. Their structures can be described as polyketide, terpenoid, peptide, alkaloid, quinone, pyrone, sterol, and fatty acid. They have been demonstrated varying biological activities, including antimicrobial, antitumor, insecticidal, antiplasmodial, antimalarial, nematicidal, herbicidal, and enzyme-inhibiting. This review provides a comprehensive overview of secondary metabolites and their biological activities from strains of .
Topics: Antineoplastic Agents; Antiparasitic Agents; Enzyme Inhibitors; Herbicides; Insecticides; Paecilomyces; Secondary Metabolism
PubMed: 33139652
DOI: 10.3390/molecules25215077 -
Microbiology Spectrum Jun 2022Higher-order spatial organization of the chromatin in the nucleus plays crucial roles in the maintenance of cell functions and the regulation of gene expression....
Higher-order spatial organization of the chromatin in the nucleus plays crucial roles in the maintenance of cell functions and the regulation of gene expression. Three-dimensional (3D) genome sequencing has been used to great effect in mammal and plants, but the availability of 3D genomes of filamentous fungi is severely limited. Here, we performed a chromosome-level genome assembly of Penicillium oxalicum through single-molecule real-time sequencing (Pacific Biosciences) and chromatin interaction mapping (Hi-C), with a scaffold of 4.07 Mb and a contig of 3.81 Mb, and further elucidated the 3D genome architecture of P. oxalicum. High-frequency interchromosomal contacts occurred within the centromeres and telomeres, as well as within individual chromosomes. There were 12,203 -interactions and 7,884 -interactions detected at a resolution of 1 kb. Moreover, a total of 1,099 topologically associated domains (or globules) were found, ranging in size from 2.0 to 76.0 kb. Interestingly, transcription factor-bound motifs were enriched in the globule boundaries. All the cellulase and xylanase genes were discretely distributed in the 3D model of the P. oxalicum genome as a result of few and -interactions. Our results from this study provide a global view of chromatin interactions in the P. oxalicum genome and will act as a resource for studying spatial regulation of gene expression in filamentous fungi. The spatial structure of chromatin plays important roles in normal cell functions and the regulation of gene expression. The three-dimensional (3D) architectures of the genomes of many mammals and plants have been elucidated, but corresponding studies on filamentous fungi, which play vital roles as decomposers of organic matter in the soil, are very limited. Penicillium oxalicum is one of the predominant cellulolytic aerobic fungi in subtropical and tropical forest soils and can secrete integrative cellulase and xylanase under integrated regulatory control, degrading plant biomass highly efficiently. In the present study, we employed Hi-C technology to construct the 3D genome model of P. oxalicum strain HP7-1 and to further investigate cellulase and xylanase as well as transcription factor genes in 3D genome. These results provide a resource to achieve a deeper understanding of cell function and the regulation of gene expression in filamentous fungi.
Topics: Cellulase; Chromatin; Fungi; Gene Expression Regulation, Fungal; Penicillium; Transcription Factors
PubMed: 35499317
DOI: 10.1128/spectrum.02121-21