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1.
Molecules ; 29(9)2024 Apr 25.
Article En | MEDLINE | ID: mdl-38731455

Phytophthora capsici is an important plant pathogenic oomycete that causes great losses to vegetable production around the world. Antofine is an important alkaloid isolated from Cynanchum komarovii Al. Iljinski and exhibits significant antifungal activity. In this study, the effect of antofine on the mycelial growth, morphology, and physiological characteristics of P. capsici was investigated using colorimetry. Meanwhile, the activity of mitochondrial respiratory chain complexes of P. capsici was evaluated following treatment with a 30% effective concentration (EC30), as well as EC50 and EC70, of antofine for 0, 12, 24, and 48 h. The results showed that antofine had a significant inhibitory effect against P. capsici, with an EC50 of 5.0795 µg/mL. After treatment with antofine at EC50 and EC70, the mycelia were rough, less full, and had obvious depression; they had an irregular protrusion structure; and they had serious wrinkles. In P. capsici, oxalic acid and exopolysaccharide contents decreased significantly, while cell membrane permeability and glycerol content increased when treated with antofine. Reactive oxygen species (ROS) entered a burst state in P. capsici after incubation with antofine for 3 h, and fluorescence intensity was 2.43 times higher than that of the control. The activities of the mitochondrial respiratory chain complex II, III, I + III, II + III, V, and citrate synthase in P. capsici were significantly inhibited following treatment with antofine (EC50 and EC70) for 48 h compared to the control. This study revealed that antofine is likely to affect the pathways related to the energy metabolism of P. capsici and thus affect the activity of respiratory chain complexes. These results increase our understanding of the action mechanism of antofine against P. capsici.


Phytophthora , Reactive Oxygen Species , Phytophthora/drug effects , Reactive Oxygen Species/metabolism , Antifungal Agents/pharmacology , Mycelium/drug effects , Mycelium/growth & development , Plant Diseases/microbiology , Plant Diseases/prevention & control , Mitochondria/drug effects , Mitochondria/metabolism
2.
Appl Microbiol Biotechnol ; 108(1): 324, 2024 May 07.
Article En | MEDLINE | ID: mdl-38713211

Laccase, a copper-containing polyphenol oxidase, is an important green biocatalyst. In this study, Laccase Lcc5 was homologous recombinantly expressed in Coprinopsis cinerea and a novel strategy of silencing chitinase gene expression was used to enhance recombinant Lcc5 extracellular yield. Two critical chitinase genes, ChiEn1 and ChiE2, were selected by analyzing the transcriptome data of C. cinerea FA2222, and their silent expression was performed by RNA interference (RNAi). It was found that silencing either ChiEn1 or ChiE2 reduced sporulation and growth rate, and increased cell wall sensitivity, but had no significant effect on mycelial branching. Among them, the extracellular laccase activity of the ChiE2-silenced engineered strain Cclcc5-antiChiE2-5 and the control Cclcc5-13 reached the highest values (38.2 and 25.5 U/mL, respectively) at 250 and 150 rpm agitation speeds, corresponding to productivity of 0.35 and 0.19 U/mL·h, respectively, in a 3-L fermenter culture. Moreover, since Cclcc5-antiChiE2-5 could withstand greater shear forces, its extracellular laccase activity was 2.6-fold higher than that of Cclcc5-13 when the agitation speed was all at 250 rpm. To our knowledge, this is the first report of enhanced recombinant laccase production in C. cinerea by silencing the chitinase gene. This study will pave the way for laccase industrial production and accelerate the development of a C. cinerea high-expression system. KEY POINTS: • ChiEn1 and ChiE2 are critical chitinase genes in C. cinerea FA2222 genome. • Chitinase gene silencing enhanced the tolerance of C. cinerea to shear forces. • High homologous production of Lcc5 is achieved by fermentation in a 3-L fermenter.


Chitinases , Gene Silencing , Laccase , Chitinases/genetics , Chitinases/metabolism , Chitinases/biosynthesis , Laccase/genetics , Laccase/metabolism , Laccase/biosynthesis , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Agaricales/genetics , Agaricales/enzymology , Fermentation , RNA Interference , Fungal Proteins/genetics , Fungal Proteins/metabolism , Mycelium/genetics , Mycelium/growth & development , Mycelium/enzymology , Cell Wall/metabolism , Cell Wall/genetics
3.
Environ Microbiol Rep ; 16(3): e13271, 2024 Jun.
Article En | MEDLINE | ID: mdl-38692852

Tuber magnatum is the most expensive truffle, but its large-scale cultivation is still a challenge compared to other valuable Tuber species. T. magnatum mycelium has never been grown profitably until now, which has led to difficulties to studying it in vitro. This study describes beneficial interactions between T. magnatum mycelium and never before described bradyrhizobia, which allows the in vitro growth of T. magnatum mycelium. Three T. magnatum strains were co-isolated on modified Woody Plant Medium (mWPM) with aerobic bacteria and characterised through microscopic observations. The difficulties of growing alone both partners, bacteria and T. magnatum mycelium, on mWPM demonstrated the reciprocal dependency. Three bacterial isolates for each T. magnatum strain were obtained and molecularly characterised by sequencing the 16S rRNA, glnII, recA and nifH genes. Phylogenetic analyses showed that all nine bacterial strains were distributed among five subclades included in a new monophyletic lineage belonging to the Bradyrhizobium genus within the Bradyrhizobium jicamae supergroup. The nifH genes were detected in all bacterial isolates, suggesting nitrogen-fixing capacities. This is the first report of consistent T. magnatum mycelium growth in vitro conditions. It has important implications for the development of new technologies in white truffle cultivation and for further studies on T. magnatum biology and genetics.


Bradyrhizobium , Mycelium , Phylogeny , RNA, Ribosomal, 16S , Bradyrhizobium/genetics , Bradyrhizobium/classification , Bradyrhizobium/isolation & purification , Bradyrhizobium/physiology , Bradyrhizobium/growth & development , Bradyrhizobium/metabolism , Mycelium/growth & development , RNA, Ribosomal, 16S/genetics , Nitrogen Fixation , DNA, Bacterial/genetics , Symbiosis
4.
Arch Microbiol ; 206(6): 273, 2024 May 22.
Article En | MEDLINE | ID: mdl-38772954

Acid protease is widely used in industries such as food processing and feed additives. In the study, low frequency magnetic field (LF-MF) as an aid enhances acid protease production by Aspergillus niger (A. niger). The study assessed mycelial biomass, the enzymic activity of the acidic protease and underlying mechanism. At low intensities, alternating magnetic field (AMF) is more effective than static magnetic fields (SMF). Under optimal magnetic field conditions, acid protease activity and biomass increased by 91.44% and 16.31%, as compared with the control, respectively. Maximum 19.87% increase in enzyme activity after magnetic field treatment of crude enzyme solution in control group. Transcriptomics analyses showed that low frequency alternating magnetic field (LF-AMF) treatment significantly upregulated genes related to hydrolases and cell growth. Our results showed that low-frequency magnetic fields can enhance the acid protease production ability of A. niger, and the effect of AMF is better at low intensities. The results revealed that the effect of magnetic field on the metabolic mechanism of A. niger and provided a reference for magnetic field-assisted fermentation of A. niger.


Aspergillus niger , Magnetic Fields , Peptide Hydrolases , Aspergillus niger/enzymology , Aspergillus niger/genetics , Peptide Hydrolases/metabolism , Peptide Hydrolases/genetics , Fermentation , Fungal Proteins/genetics , Fungal Proteins/metabolism , Biomass , Mycelium/enzymology , Mycelium/growth & development , Mycelium/genetics
5.
Sci Rep ; 14(1): 11482, 2024 05 20.
Article En | MEDLINE | ID: mdl-38769352

Presented paper deals with a novel application of the (nonlinear) logistic equation to model an elimination of microscopic filaments types of fungi-molds from affected materials via different external inactivation techniques. It is shown that if the inactivation rate of the external source is greater than the maximum natural growth rate of mycelium, the mold colony becomes destroyed after a finite time. Otherwise, the mycelium may survive the external attack only at a sufficiently large initial concentration of the inoculum. Theoretically determined growth curves are compared with the experimental data for Aspergillus brasiliensis mold inactivated by using both cold atmospheric plasma (CAP) and UV-germicidal lamp. Model presented in the article may be applied also to other classes of microorganisms (e.g. bacteria).


Aspergillus , Aspergillus/growth & development , Aspergillus/physiology , Fungi , Plasma Gases/pharmacology , Ultraviolet Rays , Models, Biological , Mycelium/growth & development
6.
Int J Biol Macromol ; 268(Pt 1): 131686, 2024 May.
Article En | MEDLINE | ID: mdl-38643923

Despite a fair amount of lignin conversion during mycelial growth, previous structural analyses have not yet revealed how lignin changes continuously and what the relationship is between lignin and ligninolytic enzymes. To clarify these aspects, Quercus acutissima sawdust attaching Ganoderma lucidum mycelium collected from different growth stage was subjected to analysis of lignin structure and ligninolytic enzyme activity. Two key periods of lignin degradation are found during the cultivation of G. lucidum: hypha rapid growth period and primordium formation period. In the first stage, laccase activity is associated with the opening of structures such as methoxyls, ß-O-4' substructures and guaiacyl units in lignin, as well as the shortening of lignin chains. Manganese peroxidases and lignin peroxidases are more suitable for degrading short chain lignin. The structure of phenylcoumarans and syringyl changes greatly in the second stage. The results from sawdust attaching mycelium provide new insights to help improve the cultivation substrate formulation of G. lucidum and understand biomass valorization better.


Lignin , Mycelium , Quercus , Reishi , Lignin/metabolism , Lignin/chemistry , Quercus/metabolism , Quercus/chemistry , Quercus/growth & development , Mycelium/metabolism , Mycelium/growth & development , Reishi/metabolism , Reishi/growth & development , Wood/chemistry , Laccase/metabolism , Peroxidases/metabolism , Biomass
7.
J Agric Food Chem ; 72(18): 10282-10294, 2024 May 08.
Article En | MEDLINE | ID: mdl-38657235

This study explores the antipathogenic properties of volatile organic compounds (VOCs) produced by Bacillus velezensis LT1, isolated from the rhizosphere soil of Coptis chinensis. The impact of these VOCs on the mycelial growth of Sclerotium rolfsii LC1, the causative agent of southern blight in C. chinensis, was evaluated using a double Petri-dish assay. The biocontrol efficacy of these VOCs was further assessed through leaf inoculation and pot experiments. Antifungal VOCs were collected using headspace solid-phase microextraction (SPME), and their components were identified via gas chromatography-mass spectrometry (GC-MS). The results revealed that the VOCs significantly inhibited the mycelial growth and sclerotia germination of S. rolfsii LC1 and disrupted the morphological integrity of fungal mycelia. Under the influence of these VOCs, genes associated with chitin synthesis were upregulated, while those related to cell wall degrading enzymes were downregulated. Notably, 2-dodecanone and 2-undecanone exhibited inhibition rates of 81.67% and 80.08%, respectively. This research provides a novel approach for the prevention and management of southern blight in C. chinensis, highlighting the potential of microbial VOCs in biocontrol strategies.


Bacillus , Basidiomycota , Coptis , Plant Diseases , Volatile Organic Compounds , Volatile Organic Compounds/chemistry , Volatile Organic Compounds/pharmacology , Volatile Organic Compounds/metabolism , Bacillus/chemistry , Bacillus/metabolism , Plant Diseases/microbiology , Plant Diseases/prevention & control , Basidiomycota/chemistry , Basidiomycota/metabolism , Coptis/chemistry , Coptis/microbiology , Fungicides, Industrial/pharmacology , Fungicides, Industrial/chemistry , Gas Chromatography-Mass Spectrometry , Mycelium/chemistry , Mycelium/growth & development , Mycelium/drug effects
8.
Microb Pathog ; 190: 106604, 2024 May.
Article En | MEDLINE | ID: mdl-38490458

Early blight caused by Alternaria solani is a common foliar disease of potato around the world, and serious infections result in reduced yields and marketability due to infected tubers. The major aim of this study is to figure out the synergistic effect between microorganism and fungicides and to evaluate the effectiveness of Bacillus subtilis NM4 in the control of early blight in potato. Based on its colonial morphology and a 16S rRNA analysis, a bacterial antagonist isolated from kimchi was identified as B. subtilis NM4 and it has strong antifungal and anti-oomycete activity against several phytopathogenic fungi and oomycetes. The culture filtrate of strain NM4 with the fungicide effectively suppressed the mycelial growth of A. solani, with the highest growth inhibition rate of 83.48%. Although exposure to culture filtrate prompted hyphal alterations in A. solani, including bulging, combining it with the fungicide caused more severe hyphal damage with continuous bulging. Surfactins and fengycins, two lipopeptide groups, were isolated and identified as the main compounds in two fractions using LC-ESI-MS. Although the surfactin-containing fraction failed to inhibit growth, the fengycin-containing fraction, alone and in combination with chlorothalonil, restricted mycelial development, producing severe hyphal deformations with formation of chlamydospores. A pot experiment combining strain NM4, applied as a broth culture, with fungicide, at half the recommended concentration, resulted in a significant reduction in potato early blight severity. Our results indicate the feasibility of an integrated approach for the management of early blight in potato that can reduce fungicide application rates, promoting a healthy ecosystem in agriculture.


Alternaria , Bacillus subtilis , Fungicides, Industrial , Lipopeptides , Nitriles , Plant Diseases , Solanum tuberosum , Solanum tuberosum/microbiology , Plant Diseases/microbiology , Plant Diseases/prevention & control , Alternaria/drug effects , Alternaria/growth & development , Bacillus subtilis/drug effects , Bacillus subtilis/growth & development , Fungicides, Industrial/pharmacology , Nitriles/pharmacology , Lipopeptides/pharmacology , RNA, Ribosomal, 16S/genetics , Hyphae/drug effects , Hyphae/growth & development , Mycelium/drug effects , Mycelium/growth & development , Peptides, Cyclic/pharmacology
9.
Z Naturforsch C J Biosci ; 79(3-4): 89-92, 2024 Mar 25.
Article En | MEDLINE | ID: mdl-38421614

A novel isocoumarin was isolated from the mycelia of the dark septate endophytic fungus Phialocephala fortinii. The chemical structure was determined to be 8-hydroxy-6-methoxy-3,7-dimethyl-1H-2-benzopyran-1-one based on mass spectrometry, 1H-nuclear magnetic resonance (NMR), and 13C-NMR spectroscopic analyses, including 2D-NMR experiments. The isolated compound inhibited root growth of Arabidopsis thaliana, suggesting its potential as a plant growth regulator.


Arabidopsis , Ascomycota , Isocoumarins , Plant Roots , Isocoumarins/chemistry , Isocoumarins/pharmacology , Isocoumarins/isolation & purification , Ascomycota/chemistry , Plant Roots/microbiology , Arabidopsis/microbiology , Magnetic Resonance Spectroscopy , Endophytes/chemistry , Mycelium/growth & development , Mycelium/chemistry , Mycelium/drug effects , Plant Growth Regulators/pharmacology , Plant Growth Regulators/chemistry , Molecular Structure
10.
Zhongguo Zhong Yao Za Zhi ; 48(10): 2732-2738, 2023 May.
Article Zh | MEDLINE | ID: mdl-37282933

In Zherong county, Fujian province, the black spot of Pseudostellaria heterophylla often breaks out in the rainy season from April to June every year. As one of the main leaf diseases of P. heterophylla, black spot seriously affects the yield and quality of the medicinal material. To identify and characterize the pathogens causing black spot, we isolated the pathogens, identified them as a species of Alternaria according to Koch's postulates, and then tested their pathogenicity and biological characteristics. The results showed that the pathogens causing P. heterophylla black spot were A. gaisen, as evidenced by the similar colony morphology, spore characteristics, sporulation phenotype, and the same clade with A. gaisen on the phylogenetic tree(the maximum likelihood support rate of 100% and the Bayesian posterior probability of 1.00) built based on the tandem sequences of ITS, tef1, gapdh, endoPG, Alta1, OPA10-2, and KOG1077. The optimum conditions for mycelial growth of the pathogen were 25 ℃, pH 5-8, and 24 h dark culture. The lethal conditions for mycelia and spores were both treatment at 50 ℃ for 10 min. We reported for the first time the A. gaisen-caused black spot of P. heterophylla. The results could provide a theoretical basis for the diagnosis and control of P. heterophylla leaf spot diseases.


Alternaria , Caryophyllaceae , Plant Diseases , Alternaria/classification , Alternaria/genetics , Alternaria/growth & development , Alternaria/pathogenicity , Caryophyllaceae/microbiology , DNA, Fungal/genetics , Mycelium/growth & development , Phylogeny , Plant Diseases/microbiology , Plant Diseases/prevention & control , China
11.
Toxins (Basel) ; 14(2)2022 02 15.
Article En | MEDLINE | ID: mdl-35202169

Fusarium graminearum is a harmful pathogen causing head blight in cereals such as wheat and barley, and thymol has been proven to inhibit the growth of many pathogens. This study aims to explore the fungistatic effect of thymol on F. graminearum and its mechanism. Different concentrations of thymol were used to treat F. graminearum. The results showed that the EC50 concentration of thymol against F. graminearum was 40 µg/mL. Compared with the control group, 40 µg/mL of thymol reduced the production of Deoxynivalenol (DON) and 3-Ac-DON by 70.1% and 78.2%, respectively. Our results indicate that thymol can effectively inhibit the growth and toxin production of F. graminearum and cause an extensive transcriptome response. Transcriptome identified 16,727 non-redundant unigenes and 1653 unigenes that COG did not annotate. The correlation coefficients between samples were all >0.941. When FC was 2.0 times, a total of 3230 differential unigenes were identified, of which 1223 were up-regulated, and 2007 were down-regulated. Through the transcriptome, we confirmed that the expression of many genes involved in F. graminearum growth and synthesis of DON and other secondary metabolites were also changed. The gluconeogenesis/glycolysis pathway may be a potential and important way for thymol to affect the growth of F. graminearum hyphae and the production of DON simultaneously.


Antifungal Agents/chemistry , Fusarium/growth & development , Fusarium/metabolism , Mycelium/drug effects , Mycelium/growth & development , Mycotoxins/biosynthesis , Mycotoxins/chemistry , Thymol/chemistry , Transcriptome
12.
Viruses ; 14(2)2022 01 20.
Article En | MEDLINE | ID: mdl-35215789

Recent studies have demonstrated that phages can be co-transported with motile non-host bacteria, thereby enabling their invasion of biofilms and control of biofilm composition. Here, we developed a novel approach to isolate non-host bacteria able to co-transport phages from soil. It is based on the capability of phage-carrying non-host bacteria to move along mycelia out of soil and form colonies in plaques of their co-transported phages. The approach was tested using two model phages of differing surface hydrophobicity, i.e., hydrophobic Escherichia virus T4 (T4) and hydrophilic Pseudoalteromonas phage HS2 (HS2). The phages were mixed into soil and allowed to be transported by soil bacteria along the mycelia of Pythium ultimum. Five phage-carrying bacterial species were isolated (Viridibacillus sp., Enterobacter sp., Serratia sp., Bacillus sp., Janthinobacterium sp.). These bacteria exhibited phage adsorption efficiencies of ≈90-95% for hydrophobic T4 and 30-95% for hydrophilic HS2. The phage adsorption efficiency of Viridibacillus sp. was ≈95% for both phages and twofold higher than T4-or HS2-adsorption to their respective hosts, qualifying Viridibacillus sp. as a potential super carrier for phages. Our approach offers an effective and target-specific way to identify and isolate phage-carrying bacteria in natural and man-made environments.


Bacteria/virology , Bacteriophages/physiology , Mycelium/virology , Bacteria/classification , Bacteria/genetics , Bacteria/isolation & purification , Bacteriophage T4/physiology , Mycelium/growth & development , Pythium/growth & development , Pythium/virology , Soil Microbiology
13.
Int J Mol Sci ; 23(3)2022 Feb 06.
Article En | MEDLINE | ID: mdl-35163762

Autophagy is ubiquitously present in eukaryotes. During this process, intracellular proteins and some waste organelles are transported into lysosomes or vacuoles for degradation, which can be reused by the cell to guarantee normal cellular metabolism. However, the function of autophagy-related (ATG) proteins in oomycetes is rarely known. In this study, we identified an autophagy-related gene, PlATG6a, encoding a 514-amino-acid protein in Peronophythora litchii, which is the most destructive pathogen of litchi. The transcriptional level of PlATG6a was relatively higher in mycelium, sporangia, zoospores and cysts. We generated PlATG6a knockout mutants using CRISPR/Cas9 technology. The P. litchii Δplatg6a mutants were significantly impaired in autophagy and vegetative growth. We further found that the Δplatg6a mutants displayed decreased branches of sporangiophore, leading to impaired sporangium production. PlATG6a is also involved in resistance to oxidative and salt stresses, but not in sexual reproduction. The transcription of peroxidase-encoding genes was down-regulated in Δplatg6a mutants, which is likely responsible for hypersensitivity to oxidative stress. Compared with the wild-type strain, the Δplatg6a mutants showed reduced virulence when inoculated on the litchi leaves using mycelia plugs. Overall, these results suggest a critical role for PlATG6a in autophagy, vegetative growth, sporangium production, sporangiophore development, zoospore release, pathogenesis and tolerance to salt and oxidative stresses in P. litchii.


Beclin-1/genetics , Litchi/growth & development , Phytophthora/growth & development , Up-Regulation , Autophagy , CRISPR-Cas Systems , Gene Knockout Techniques , Litchi/parasitology , Mycelium/genetics , Mycelium/growth & development , Mycelium/pathogenicity , Oxidative Stress , Phytophthora/genetics , Phytophthora/pathogenicity , Plant Leaves/growth & development , Plant Leaves/parasitology , Reproduction, Asexual , Salt Tolerance , Virulence Factors/genetics
14.
PLoS One ; 17(1): e0262836, 2022.
Article En | MEDLINE | ID: mdl-35051224

Alternaria porri (Ellis) Clf. causes purple blotch disease on Allium plants which results in the reduction of crop yields and quality. In this study, to efficiently find natural antifungal compounds against A. porri, we optimized the culture condition for the spore production of A. porri and the disease development condition for an in vivo antifungal assay. From tested plant materials, the methanol extracts derived from ten plant species belonging to the families Cupressaceae, Fabaceae, Dipterocarpaceae, Apocynaceae, Lauraceae, and Melastomataceae were selected as potent antifungal agents against A. porri. In particular, the methanol extract of Caryodaphnopsis baviensis (Lec.) A.-Shaw completely inhibited the growth of A. porri at a concentration of 111 µg/ml. Based on chromatographic and spectroscopic analyses, a neolignan compound magnolol was identified as the antifungal compound of the C. baviensis methanol extract. Magnolol showed a significant inhibitory activity against the spore germination and mycelial growth of A. porri with IC50 values of 4.5 and 5.4 µg/ml, respectively. Furthermore, when magnolol was sprayed onto onion plants at a concentration of 500 µg/ml, it showed more than an 80% disease control efficacy for the purple blotch diseases. In terms of the antifungal mechanism of magnolol, we explored the in vitro inhibitory activity on individual oxidative phosphorylation complexes I-V, and the results showed that magnolol acts as multiple inhibitors of complexes I-V. Taken together, our results provide new insight into the potential of magnolol as an active ingredient with antifungal inhibitory action to control purple blotch on onions.


Alternaria/drug effects , Antifungal Agents/pharmacology , Biphenyl Compounds/pharmacology , Lauraceae/chemistry , Lignans/pharmacology , Onions/microbiology , Plant Diseases/microbiology , Plant Extracts/pharmacology , Methanol/chemistry , Mycelium/drug effects , Mycelium/growth & development
15.
Bioengineered ; 13(2): 3284-3299, 2022 02.
Article En | MEDLINE | ID: mdl-35100087

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 vg1 = 0.12 and the environmental-holding capacity k1 = 3000; vg2 = 0.15 and k2 = 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.


Ecosystem , Fungi/growth & development , Models, Biological , Mycelium/growth & development , Wood/microbiology
16.
Sci Rep ; 12(1): 340, 2022 01 10.
Article En | MEDLINE | ID: mdl-35013424

Electrical activity of fungus Pleurotus ostreatus is characterised by slow (h) irregular waves of baseline potential drift and fast (min) action potential likes spikes of the electrical potential. An exposure of the myceliated substrate to a chloroform vapour lead to several fold decrease of the baseline potential waves and increase of their duration. The chloroform vapour also causes either complete cessation of spiking activity or substantial reduction of the spiking frequency. Removal of the chloroform vapour from the growth containers leads to a gradual restoration of the mycelium electrical activity.


Action Potentials/drug effects , Anesthetics, Inhalation/pharmacology , Chloroform/pharmacology , Mycelium/drug effects , Pleurotus/drug effects , Mycelium/growth & development , Pleurotus/growth & development , Time Factors , Volatilization
17.
Microbiol Spectr ; 10(1): e0006321, 2022 02 23.
Article En | MEDLINE | ID: mdl-34985327

Filamentous fungi form multicellular hyphae, which generally form pellets in liquid shake cultures, during the vegetative growth stage. Because of these characteristics, growth-monitoring methods commonly used in bacteria and yeast have not been applied to filamentous fungi. We have recently revealed that the cell wall polysaccharide α-1,3-glucan and extracellular polysaccharide galactosaminogalactan (GAG) contribute to hyphal aggregation in Aspergillus oryzae. Here, we tested whether Aspergillus fumigatus shows dispersed growth in liquid media that can be quantitatively monitored, similar to that of yeasts. We constructed a double disruptant mutant of both the primary α-1,3-glucan synthase gene ags1 and the putative GAG synthase gene gtb3 in A. fumigatus AfS35 and found that the hyphae of this mutant were fully dispersed. Although the mutant lost α-1,3-glucan and GAG, its growth and susceptibility to antifungal agents were not different from those of the parental strain. Mycelial weight of the mutant in shake-flask cultures was proportional to optical density for at least 18 h. We were also able to quantify the dose response of hyphal growth to antifungal agents by measuring optical density. Overall, we established a convenient strategy to monitor A. fumigatus hyphal growth. Our method can be directly used for screening for novel antifungals against Aspergillus species. IMPORTANCE Filamentous fungi generally form hyphal pellets in liquid culture. This property prevents filamentous fungi so that we may apply the methods used for unicellular organisms such as yeast and bacteria. In the present study, by using the fungal pathogen Aspergillus fumigatus strain with modified hyphal surface polysaccharides, we succeeded in monitoring the hyphal growth quantitatively by optical density. The principle of this easy measurement by optical density could lead to a novel standard of hyphal quantification such as those that have been used for yeasts and bacteria. Dose response of hyphal growth by antifungal agents could also be monitored. This method could be useful for screening for novel antifungal reagents against Aspergillus species.


Aspergillus fumigatus/chemistry , Aspergillus fumigatus/growth & development , Culture Media/metabolism , Spectrophotometry/methods , Antifungal Agents/pharmacology , Aspergillus fumigatus/drug effects , Aspergillus fumigatus/genetics , Cell Wall/genetics , Cell Wall/metabolism , Culture Media/chemistry , Fungal Proteins/genetics , Fungal Proteins/metabolism , Glucans/metabolism , Glucosyltransferases/genetics , Glucosyltransferases/metabolism , Hyphae/chemistry , Hyphae/drug effects , Hyphae/genetics , Hyphae/growth & development , Mycelium/chemistry , Mycelium/drug effects , Mycelium/genetics , Mycelium/growth & development
18.
Molecules ; 27(1)2022 Jan 03.
Article En | MEDLINE | ID: mdl-35011507

Fungal mycelium cultures are an alternative to natural sources in order to obtain valuable research materials. They also enable constant control and adaptation of the process, thereby leading to increased biomass growth and accumulation of bioactive metabolites. The present study aims to assess the biosynthetic potential of mycelial cultures of six Ganoderma species: G. adspersum, G. applanatum, G. carnosum, G. lucidum, G. pfeifferi, and G. resinaceum. The presence of phenolic acids, amino acids, indole compounds, sterols, and kojic acid in biomass extracts was determined by HPLC. The antioxidant and cytotoxic activities of the extracts and their effects on the inhibition of selected enzymes (tyrosinase and acetylcholinesterase) were also evaluated. The total content of phenolic acids in the extracts ranged from 5.8 (G. carnosum) to 114.07 mg/100 g dry weight (d.w.) (G. pfeifferi). The total content of indole compounds in the extracts ranged from 3.03 (G. carnosum) to 11.56 mg/100 g d.w. (G. lucidum) and that of ergosterol ranged from 28.15 (G. applanatum) to 74.78 mg/100 g d.w. (G. adspersum). Kojic acid was found in the extracts of G. applanatum and G. lucidum. The tested extracts showed significant antioxidant activity. The results suggest that the analyzed mycelial cultures are promising candidates for the development of new dietary supplements or pharmaceutical preparations.


Antioxidants/chemistry , Cholinesterase Inhibitors/chemistry , Complex Mixtures/chemistry , Cytotoxins/chemistry , Ganoderma/chemistry , Mycelium/chemistry , Animals , Antioxidants/pharmacology , Cholinesterase Inhibitors/pharmacology , Complex Mixtures/pharmacology , Cytotoxins/pharmacology , Ganoderma/growth & development , Melanoma, Experimental/metabolism , Mice , Monophenol Monooxygenase/antagonists & inhibitors , Mycelium/growth & development
19.
J Toxicol Environ Health A ; 85(2): 43-55, 2022 01 17.
Article En | MEDLINE | ID: mdl-34459359

Monilinia fructicola (Wint.) Honey is a plant pathogenic fungus that infects stone fruits such as peach, nectarine and plum, which are high demand cultivars found in Brazil. This pathogen may remain latent in the host, showing no apparent signs of disease, and consequently may spread to different countries. The aim of this study was to evaluate the activity of hydroalcoholic extract (HydE) obtained from Lactarius deliciosus (L.) Sf. Gray a mushroom, against M. fructicola phytopathogenic-induced mycelial growth. In addition, the purpose of this study was to examine phytotoxicity attributed to HydE using Brassica oleracea seeds, as well as cytotoxic analysis of this extract on cells of mouse BALB/c monocyte macrophage cell line (J774A.1 cell line) (ATCC TIB-67). The L. deliciosus HydE inhibited fungal growth and reduced phytopathogen mycelial development at a concentration of 1.25 mg/ml. Our results demonstrated that the extract exhibited phytotoxicity as evidenced by (1) interference on germination percentage and rate index, (2) decreased root and initial growth measures, and (3) lower fresh weight of seedlings but no cytotoxicity in Vero cell lines. Data suggest that the use of the L. deliciosus extracts may be beneficial for fungal control without any apparent adverse actions on mouse BALB/c monocyte macrophage cell line (J774A.1 cell line) viability.


Antifungal Agents/pharmacology , Basidiomycota/chemistry , Biological Control Agents/pharmacology , Animals , Antifungal Agents/chemistry , Ascomycota/drug effects , Ascomycota/growth & development , Biological Control Agents/chemistry , Brazil , Cell Line , Cell Survival/drug effects , Free Radical Scavengers/chemistry , Free Radical Scavengers/pharmacology , Fruit/microbiology , Germination/drug effects , Mice , Mycelium/drug effects , Mycelium/growth & development , Phenol/analysis , Plant Diseases/microbiology , Seeds/growth & development , Seeds/microbiology
20.
Sci Rep ; 11(1): 24157, 2021 12 17.
Article En | MEDLINE | ID: mdl-34921189

The microbial food fermentation industry requires real-time monitoring and accurate quantification of cells. However, filamentous fungi are difficult to quantify as they have complex cell types such as pellet, spores, and dispersed hyphae. In this study, numerous data of microscopic image intensity (MII) were used to develop a simple and accurate quantification method of Cordyceps mycelium. The dry cell weight (DCW) of the sample collected during the fermentation was measured. In addition, the intensity values were obtained through the ImageJ program after converting the microscopic images. The prediction model obtained by analyzing the correlation between MII and DCW was evaluated through a simple linear regression method and found to be statistically significant (R2 = 0.941, p < 0.001). In addition, validation with randomly selected samples showed significant accuracy, thus, this model is expected to be used as a valuable tool for predicting and quantifying fungal growth in various industries.


Cordyceps , Models, Biological , Mycelium , Cordyceps/cytology , Cordyceps/growth & development , Mycelium/cytology , Mycelium/growth & development
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