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Microbiology Spectrum Sep 2021Aspergillus oryzae is a safe filamentous fungus widely used in the food, medicine, and feed industries, but there is currently not enough research on the light response...
Aspergillus oryzae is a safe filamentous fungus widely used in the food, medicine, and feed industries, but there is currently not enough research on the light response of A. oryzae. In this study, 12 different light conditions were set and A. oryzae GDMCC 3.31 was continuously irradiated for 72 h to investigate the effect of light on mycelial growth and conidium production. Specifically, each light condition was the combination of one light wavelength (475, 520, or 630 nm) and one light intensity (20, 40, 60, or 80 μmol photon m s). The results show that mycelium growth was inhibited significantly by green light (wavelength of 520 nm and intensities of 20 and 60 μmol photon m s) and blue light (wavelength of 475 nm and intensity of 80 μmol photon m s). The production of conidia was suppressed only by blue light (wavelength of 475 nm and intensities of 40, 60, and 80 μmol photon m s), and those levels of inhibition increased when the intensity of blue light increased. When the strain was irradiated by blue light (80 μmol photon m s), the number of conidia was 57.4% less than that of the darkness group. However, within our set range of light intensities, A. oryzae GDMCC 3.31 was insensitive to red light (wavelength of 630 nm) in terms of mycelium growth and conidium production. Moreover, interaction effects between light wavelength and intensity were found to exist in terms of colony diameter and the number of conidia. This research investigated the light response of A. oryzae, which may provide a new method to regulate mixed strains in fermented foods by light. Studies on the monochromatic light response of Aspergillus nidulans and Neurospora crassa have gone deep into the molecular mechanism. However, research methods for the light response of A. oryzae remain in the use of white light sources. In this study, we first demonstrated that A. oryzae GDMCC 3.31 was sensitive to light wavelength and intensity. We have observed that blue light inhibited its growth and sporulation and the inhibitory effect increased with intensity. This research not only adds new content to the study of the photoreaction of Aspergillus but also brings new possibilities for the use of light to regulate mixed strains and ultimately improve the flavor quality of fermented foods.
Topics: Aspergillus oryzae; Light; Mycelium; Spores, Fungal
PubMed: 34346745
DOI: 10.1128/Spectrum.00213-21 -
Communications Biology Mar 2022The direct delivery of molecules and the sampling of endogenous compounds into and from living cells provide powerful means to modulate and study cellular functions....
The direct delivery of molecules and the sampling of endogenous compounds into and from living cells provide powerful means to modulate and study cellular functions. Intracellular injection and extraction remain challenging for fungal cells that possess a cell wall. The most common methods for intracellular delivery into fungi rely on the initial degradation of the cell wall to generate protoplasts, a step that represents a major bottleneck in terms of time, efficiency, standardization, and cell viability. Here, we show that fluidic force microscopy enables the injection of solutions and cytoplasmic fluid extraction into and out of individual fungal cells, including unicellular model yeasts and multicellular filamentous fungi. The approach is strain- and cargo-independent and opens new opportunities for manipulating and analyzing fungi. We also perturb individual hyphal compartments within intact mycelial networks to study the cellular response at the single cell level.
Topics: Cell Wall; Fungi; Hyphae; Mycelium; Yeasts
PubMed: 35233064
DOI: 10.1038/s42003-022-03127-z -
ELife Jul 2019Mutualistic interactions between free-living algae and fungi are widespread in nature and are hypothesized to have facilitated the evolution of land plants and lichens....
Mutualistic interactions between free-living algae and fungi are widespread in nature and are hypothesized to have facilitated the evolution of land plants and lichens. In all known algal-fungal mutualisms, including lichens, algal cells remain external to fungal cells. Here, we report on an algal-fungal interaction in which algal cells become internalized within the hyphae of the fungus . This apparent symbiosis begins with close physical contact and nutrient exchange, including carbon and nitrogen transfer between fungal and algal cells as demonstrated by isotope tracer experiments. This mutualism appears to be stable, as both partners remain physiologically active over months of co-cultivation, leading to the eventual internalization of photosynthetic algal cells, which persist to function, grow and divide within fungal hyphae. and are biotechnologically important species for lipids and biofuel production, with available genomes and molecular tool kits. Based on the current observations, they provide unique opportunities for studying fungal-algal mutualisms including mechanisms leading to endosymbiosis.
Topics: Biofuels; Endocytosis; Lipid Metabolism; Mortierella; Mycelium; Photosynthesis; Stramenopiles; Symbiosis
PubMed: 31307571
DOI: 10.7554/eLife.47815 -
Scientific Reports Mar 2019Novel hybrid panel composites based on wood, fungal mycelium, and cellulose nanofibrils (CNF) were developed and investigated in the present study. In one set of...
Novel hybrid panel composites based on wood, fungal mycelium, and cellulose nanofibrils (CNF) were developed and investigated in the present study. In one set of experiments, mycelium was grown on softwood particles to produce mycelium-modified wood which was then hybridized with various levels of CNF as binder. The other set of experiments were conducted on unmodified wood particles mixed with CNF and pure mycelium tissue. It was found that the composites made of mycelium-modified wood and CNF resulted in enhanced physical and mechanical properties compared to the ones made by physically mixing wood, mycelium, and CNF. Scanning electron microscopy (SEM) images showed that mycelium modification covered wood particles with a network of fungal hyphae whereas CNF formed a uniform mycelial film over wood particles. Mycelium modification had a significant effect on reducing water absorption and thickness swelling of the hybrid composites and CNF increased the modulus of rupture and modulus of elasticity, optimally at 2.5% addition. We also present results and analysis pertaining to the development of unique lightweight composite systems with physical and mechanical properties optimized at 5% CNF addition with potential to be used in packaging and furniture applications.
Topics: Cellulose; Microscopy, Electron, Scanning; Mycelium; Nanofibers; Particle Size; Tensile Strength; Wood
PubMed: 30842558
DOI: 10.1038/s41598-019-40442-8 -
Communications Biology May 2021Streptomyces are one of the most important industrial microorganisms for the production of proteins and small-molecule drugs. Previously reported flow cytometry-based...
Streptomyces are one of the most important industrial microorganisms for the production of proteins and small-molecule drugs. Previously reported flow cytometry-based screening methods can only screen spores or protoplasts released from mycelium, which do not represent the filamentous stationary phase Streptomyces used in industrial cultivation. Here we show a droplet-based microfluidic platform to facilitate more relevant, reliable and rapid screening of Streptomyces mycelium, and achieved an enrichment ratio of up to 334.2. Using this platform, we rapidly characterized a series of native and heterologous constitutive promoters in Streptomyces lividans 66 in droplets, and efficiently screened out a set of engineered promoter variants with desired strengths from two synthetic promoter libraries. We also successfully screened out several hyperproducers of cellulases from a random S. lividans 66 mutant library, which had 69.2-111.4% greater cellulase production than the wild type. Our method provides a fast, simple, and powerful solution for the industrial engineering and screening of Streptomyces in more industry-relevant conditions.
Topics: High-Throughput Screening Assays; Metabolic Engineering; Microfluidics; Mycelium; Promoter Regions, Genetic; Streptomyces; Streptomyces lividans
PubMed: 34059751
DOI: 10.1038/s42003-021-02186-y -
Nature Communications Jun 2017Fungal-bacterial interactions are highly diverse and contribute to many ecosystem processes. Their emergence under common environmental stress scenarios however, remains...
Fungal-bacterial interactions are highly diverse and contribute to many ecosystem processes. Their emergence under common environmental stress scenarios however, remains elusive. Here we use a synthetic microbial ecosystem based on the germination of Bacillus subtilis spores to examine whether fungal and fungal-like (oomycete) mycelia reduce bacterial water and nutrient stress in an otherwise dry and nutrient-poor microhabitat. We find that the presence of mycelia enables the germination and subsequent growth of bacterial spores near the hyphae. Using a combination of time of flight- and nanoscale secondary ion mass spectrometry (ToF- and nanoSIMS) coupled with stable isotope labelling, we link spore germination to hyphal transfer of water, carbon and nitrogen. Our study provides direct experimental evidence for the stimulation of bacterial activity by mycelial supply of scarce resources in dry and nutrient-free environments. We propose that mycelia may stimulate bacterial activity and thus contribute to sustaining ecosystem functioning in stressed habitats.
Topics: Bacillus subtilis; Basidiomycota; Carbon; Ecosystem; Fusarium; Isotopes; Mycelium; Nitrogen; Pythium; Spectrometry, Mass, Secondary Ion; Spores, Bacterial; Water
PubMed: 28589950
DOI: 10.1038/ncomms15472 -
PloS One 2019The current physical goods economy produces materials by extracting finite valuable resources without taking their end of the life and environmental impact into account....
The current physical goods economy produces materials by extracting finite valuable resources without taking their end of the life and environmental impact into account. Mycelium-based materials offer an alternative fabrication paradigm, based on the growth of materials rather than on extraction. Agricultural residue fibres are inoculated with fungal mycelium, which form an interwoven three-dimensional filamentous network binding the feedstock into a lightweight material. The mycelium-based material is heat-killed after the growing process. In this paper, we investigate the production process, the mechanical, physical and chemical properties of mycelium-based composites made with different types of lignocellulosic reinforcement fibres combined with a white rot fungus, Trametes versicolor. This is the first study reporting the dry density, the Young's modulus, the compressive stiffness, the stress-strain curves, the thermal conductivity, the water absorption rate and a FTIR analyse of mycelium-based composites by making use of a fully disclosed protocol with T. versicolor and five different type of fibres (hemp, flax, flax waste, softwood, straw) and fibre processings (loose, chopped, dust, pre-compressed and tow). The thermal conductivity and water absorption coefficient of the mycelium composites with flax, hemp, and straw have an overall good insulation behaviour in all the aspects compared to conventional materials such as rock wool, glass wool and extruded polystyrene. The conducted tests reveal that the mechanical performance of the mycelium-based composites depends more on the fibre processing (loose, chopped, pre-compressed, and tow), and size than on the chemical composition of the fibres. These experimental results show that mycelium-composites can fulfil the requirements of thermal insulation and have the potential to replace fosile-based composites. The methology used to evaluate the suitability and selection of organic waste-streams proved to be effective for the mycelium-material manufacturing applications.
Topics: Lignin; Mycelium; Tensile Strength; Trametes
PubMed: 31329589
DOI: 10.1371/journal.pone.0213954 -
Bioengineered Feb 2022Fungi play a significant role in wood fiber degradation since they possess enzymatic tools for the degradation of recalcitrant plant polymers. The study aims to...
Fungi play a significant role in wood fiber degradation since they possess enzymatic tools for the degradation of recalcitrant plant polymers. The study aims to demonstrate the interactive fungal traits when they grow together and its development with total dead wood fiber degradation speed. A lab experiment was designed to describe decomposition rates and fungal properties using nonlinear fitting model and logistic equation from preliminary data sets. The degradation speed of five (A, B, C, D, and E) different types of fungi with different growth rates were calculated at various relative humidity's (35, 50, 65, 80, and 95 g.kg). Results showed that the mycelium length of fungus A, has faster ideal growth rate than that of fungus B, with ecological niche width A < B. Besides this the growth rate of fungus 1 was 1 = 0.12 and the environmental-holding capacity 1 = 3000; 2 = 0.15 and 2 = 2000 for fungus 2. Comparing the results of fiber decomposition with a single fungus, we were able to find that the overall efficiency of the two-fungal system decomposition model was higher in a defined environment. Besides this the successfully simulated the competitive relationship between different species of fungi and the effect of different environments on the decomposition rate of fungi, with a good fit and in accordance with the biological laws. Our model is well generalizable and can be extended to multiple environmental variables (light, temperature, and heat) with good accuracy.
Topics: Ecosystem; Fungi; Models, Biological; Mycelium; Wood
PubMed: 35100087
DOI: 10.1080/21655979.2022.2025699 -
Journal of Proteomics Jan 2014The necrotrophic fungus Botrytis cinerea is a very damaging phytopathogen of wide host range and environmental persistence. It is difficult to control because of its...
UNLABELLED
The necrotrophic fungus Botrytis cinerea is a very damaging phytopathogen of wide host range and environmental persistence. It is difficult to control because of its genetic versatility, expressed in the many phenotypical differences among isolates. The genomes of the B. cinerea B05.10 and T4 strains have been recently sequenced, becoming a model system for necrotrophic pathogens, and thus opening new alternatives for functional genomics analysis. In this work, the mycelium and secreted proteome of six wild-type strains with different host range, and grown in liquid minimal medium, have been analyzed by using complementary gel-based (1-DE and 2-DE) and gel-free/label-free (nUPLC-MS(E)) approaches. We found differences in the protein profiles among strains belonging to both the mycelium and the secretome. A total of 47 and 51 variable proteins were identified in the mycelium and the secretome, respectively. Some of them, such as malate dehydrogenase or peptidyl-prolyl cis-trans isomerase from the mycelium, and endopolygalacturonase, aspartic protease or cerato-platanin protein from the secretome have been reported as virulence factors, which are involved in host-tissue invasion, pathogenicity or fungal development.
BIOLOGICAL SIGNIFICANCE
The necrotrophic fungus Botrytis cinerea is an important phytopathogen of wide host range and environmental persistence, causing substantial economic losses worldwide. In this work, the mycelium and secreted proteome of six B. cinerea wild-type strains with different host range have been analyzed by using complementary gel-based and gel-free/label-free approaches. Fungal genetic versatility was confirmed at the proteome level for both mycelium proteome and secreted proteins. A high number of hypothetical proteins with conserved domains related to toxin compounds or to unknown functions were identified, having qualitative differences among strains. The identification of hypothetical proteins suggests that the B. cinerea strains differ mostly in processes involved in adaptation to a particular environment or a growth condition, rather than in essential metabolic reactions. Proteomics can help in the identification of variable proteins related to the infection and colonization of host plant tissues, as well as of virulence and aggressiveness factors among different B. cinerea wild-type strains. This article is part of a Special Issue entitled: Trends in Microbial Proteomics.
Topics: Botrytis; Fungal Proteins; Genetic Variation; Genome, Fungal; Mycelium; Proteomics
PubMed: 23811051
DOI: 10.1016/j.jprot.2013.06.022 -
International Microbiology : the... Jan 2021Sporothrix schenckii is a thermally dimorphic fungus. In a saprotrophic environment or culturing at 25 °C, it grows as mycelia, whereas in host tissues or culturing at...
PURPOSE
Sporothrix schenckii is a thermally dimorphic fungus. In a saprotrophic environment or culturing at 25 °C, it grows as mycelia, whereas in host tissues or culturing at 37 °C, it undergoes dimorphic transition and division into pathogenic yeast cells. S. schenckii can cause serious disseminated sporotrichosis in immunocompromised hosts and presents an emerging global health problem. The mycelium-to-yeast transition was a consequence of the adaptive process to different environment. Some studies showed that the transition was significantly related to the virulence and pathogenesis of dimorphic fungi. However the genetic mechanisms of this complicated biological process are poorly understood.
METHOD
Our study presented a comparative transcriptomic analysis perspective on temperature stress in a visceral isolates of S. schenckii, obtaining more genetic information related to dimorphic transition.
RESULTS
The 9.38 Gbp dataset was generated and assembled into 14,423 unigenes. Compared with gene and protein databases, 9561 unigenes were annotated. Comparative analysis identified 1259 genes expressed differentially in mycelium and yeast phase, and were categorized into a number of important biological processes, such as synthesis and metabolism, transmembrane transport, biocatalysis, oxidation reduction, and cellular signal transduction.
CONCLUSIONS
The findings suggested that temperature-dependent transition was tightly associated with stress adaptation, growth and development, signal regulation, adhesion, and colonization, which was predicted to be related with virulence and pathogenesis. Collection of these data should offer fine-scale insights into the mechanisms of dimorphism and pathogenesis of S. schenckii, and meanwhile facilitate the evolutionary and function studies of other dimorphic fungi.
Topics: Animals; Fungal Proteins; Gene Expression Profiling; Gene Expression Regulation, Developmental; Gene Expression Regulation, Fungal; Humans; Mycelium; Sporothrix; Sporotrichosis; Stress, Physiological; Temperature; Transcription, Genetic
PubMed: 32691258
DOI: 10.1007/s10123-020-00136-y