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1.
Food Microbiol ; 122: 104551, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38839219

ABSTRACT

Brown rot, caused by Monilinia fructicola, is considered one of the devasting diseases of pre-harvest and post-harvest peach fruits, restricting the yield and quality of peach fruits and causing great economic losses to the peach industry every year. Presently, the management of the disease relies heavily on chemical control. In the study, we demonstrated that the volatile organic compounds (VOCs) of endophyte bacterial Pseudomonas protegens QNF1 inhibited the mycelial growth of M. fructicola by 95.35% compared to the control, thereby reducing the brown rot on postharvest fruits by 98.76%. Additionally, QNF1 VOCs severely damaged the mycelia of M. fructicola. RNA-seq analysis revealed that QNF1 VOCs significantly repressed the expressions of most of the genes related to pathogenesis (GO:0009405) and integral component of plasma membrane (GO:0005887), and further analysis revealed that QNF1 VOCs significantly altered the expressions of the genes involved in various metabolism pathways including Amino acid metabolism, Carbohydrate metabolism, and Lipid metabolism. The findings of the study indicated that QNF1 VOCs displayed substantial control efficacy by disrupting the mycelial morphology of M. fructicola, weakening its pathogenesis, and causing its metabolic disorders. The study provided a potential way and theoretical support for the management of the brown rot of peach fruits.


Subject(s)
Ascomycota , Fruit , Plant Diseases , Prunus persica , Pseudomonas , Volatile Organic Compounds , Volatile Organic Compounds/pharmacology , Volatile Organic Compounds/metabolism , Prunus persica/microbiology , Fruit/microbiology , Plant Diseases/microbiology , Plant Diseases/prevention & control , Pseudomonas/genetics , Pseudomonas/metabolism , Ascomycota/genetics , Ascomycota/drug effects , Ascomycota/growth & development , Ascomycota/metabolism , Mycelium/growth & development , Mycelium/drug effects , Mycelium/genetics , Endophytes/genetics , Endophytes/metabolism
2.
Environ Microbiol Rep ; 16(3): e13286, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38844388

ABSTRACT

Microorganisms in the rhizosphere, particularly arbuscular mycorrhiza, have a broad symbiotic relationship with their host plants. One of the major fungi isolated from the rhizosphere of Peucedanum praeruptorum is Penicillium restrictum. The relationship between the metabolites of P. restrictum and the root exudates of P. praeruptorum is being investigated. The accumulation of metabolites in the mycelium and fermentation broth of P. restrictum was analysed over different fermentation periods. Non-targeted metabolomics was used to compare the differences in intracellular and extracellular metabolites over six periods. There were significant differences in the content and types of mycelial metabolites during the incubation. Marmesin, an important intermediate in the biosynthesis of coumarins, was found in the highest amount on the fourth day of incubation. The differential metabolites were screened to obtain 799 intracellular and 468 extracellular differential metabolites. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that the highly enriched extracellular metabolic pathways were alanine, aspartate and glutamate metabolism, glyoxylate and dicarboxylate metabolism, and terpenoid backbone biosynthesis. In addition, the enrichment analysis associated with intracellular and extracellular ATP-binding cassette transporter proteins revealed that some ATP-binding cassette transporters may be involved in the transportation of certain amino acids and carbohydrates. Our results provide some theoretical basis for the regulatory mechanisms between the rhizosphere and the host plant and pave the way for the heterologous production of furanocoumarin.


Subject(s)
Fermentation , Mycelium , Penicillium , Rhizosphere , Mycelium/metabolism , Mycelium/growth & development , Penicillium/metabolism , Penicillium/genetics , Plant Roots/microbiology , Metabolome , Metabolomics , Soil Microbiology , Metabolic Networks and Pathways/genetics
3.
Environ Microbiol Rep ; 16(3): e13271, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38692852

ABSTRACT

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.


Subject(s)
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 in English | MEDLINE | ID: mdl-38772954

ABSTRACT

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.


Subject(s)
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): 11867, 2024 05 24.
Article in English | MEDLINE | ID: mdl-38789584

ABSTRACT

The ecological and economic benefits of mycelium composites offer a promising opportunity for supporting sustainable development in Africa. This study focuses on assessing the environmental impact of mycelium composites for building and construction (MCBs) by conducting a life cycle assessment (LCA) in the context of Africa. It is demonstrated that the potential environmental impact of MCBs is substantially influenced by the use and source of electrical power for autoclaves, incubators, and ovens, making the culturing and post-processing phases the major environmental hotspots. The impact of MCB production is also relative to the energy mix of specific countries, being higher in countries that rely on fossil fuel energy (e.g., South Africa) and lower in those that rely more on renewable sources (e.g., Democratic Republic of the Congo, DRC). Furthermore, the impact of MCB production is found to be sensitive to travel distance, suggesting that situating production facilities closer to agricultural, agro-industrial, and/or forestry waste sources could be more beneficial than interregional sourcing, for example. It is also demonstrated that MCBs have the potential to be a more ecologically sustainable alternative to some conventional construction materials (e.g., concrete) over an entire life cycle. Based on the insights obtained from this LCA, some recommendations have been proposed to address potential environmental repercussions pre-emptively and proactively: this is particularly important for nations, mainly in the Global South, that exhibit low resilience to climate change due to limited economic resources. Furthermore, with the rapid expansion of mycelium composite technology, there is a need to increase awareness about its potential environmental impact and, ultimately, to mitigate its potential contribution to pressing environmental concerns (e.g., global warming and climate change). Consequently, this study also adds to the existing body of literature on LCA studies, delineating key factors for consideration in future LCA studies and providing guidance for the sustainable establishment and expansion of this technology.


Subject(s)
Construction Materials , Mycelium , Mycelium/growth & development , Africa , Environment , Sustainable Development
6.
Appl Microbiol Biotechnol ; 108(1): 324, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38713211

ABSTRACT

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.


Subject(s)
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
7.
Int J Biol Macromol ; 270(Pt 2): 132227, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38734339

ABSTRACT

Fusarium crown rot, caused by Fusarium pseudograminearum, is a devastating disease affecting the yield and quality of cereal crops. Peroxisomes are single-membrane organelles that play a critical role in various biological processes in eukaryotic cells. To functionally characterise peroxisome biosynthetic receptor proteins FpPEX5 and FpPEX7 in F. pseudograminearum, we constructed deletion mutants, ΔFpPEX5 and ΔFpPEX7, and complementary strains, ΔFpPEX5-C and ΔFpPEX7-C, and analysed the functions of FpPEX5 and FpPEX7 proteins using various phenotypic observations. The deletion of FpPEX5 and FpPEX7 resulted in a significant deficiency in mycelial growth and conidiation and blocked the peroxisomal targeting signal 1 and peroxisomal targeting signal 2 pathways, which are involved in peroxisomal matrix protein transport, increasing the accumulation of lipid droplets and reactive oxygen species. The deletion of FpPEX5 and FpPEX7 may reduce the formation of toxigenic bodies and decrease the pathogenicity of F. pseudograminearum. These results indicate that FpPEX5 and FpPEX7 play vital roles in the growth, asexual reproduction, virulence, and fatty acid utilisation of F. pseudograminearum. This study provides a theoretical basis for controlling stem rot in wheat.


Subject(s)
Fungal Proteins , Fusarium , Peroxisomes , Fusarium/pathogenicity , Fusarium/genetics , Fusarium/metabolism , Fusarium/growth & development , Fungal Proteins/genetics , Fungal Proteins/metabolism , Virulence/genetics , Peroxisomes/metabolism , Peroxisomes/genetics , Trichothecenes/metabolism , Plant Diseases/microbiology , Spores, Fungal/growth & development , Triticum/microbiology , Reactive Oxygen Species/metabolism , Peroxisome-Targeting Signal 1 Receptor/genetics , Peroxisome-Targeting Signal 1 Receptor/metabolism , Gene Deletion , Gene Expression Regulation, Fungal , Peroxisomal Targeting Signal 2 Receptor , Mycelium/growth & development , Mycelium/metabolism
8.
Molecules ; 29(9)2024 Apr 25.
Article in English | MEDLINE | ID: mdl-38731455

ABSTRACT

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.


Subject(s)
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
9.
Sci Rep ; 14(1): 11482, 2024 05 20.
Article in English | MEDLINE | ID: mdl-38769352

ABSTRACT

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).


Subject(s)
Aspergillus , Aspergillus/growth & development , Aspergillus/physiology , Fungi , Plasma Gases/pharmacology , Ultraviolet Rays , Models, Biological , Mycelium/growth & development
10.
J Agric Food Chem ; 72(18): 10282-10294, 2024 May 08.
Article in English | MEDLINE | ID: mdl-38657235

ABSTRACT

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.


Subject(s)
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
11.
Int J Biol Macromol ; 268(Pt 1): 131686, 2024 May.
Article in English | MEDLINE | ID: mdl-38643923

ABSTRACT

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.


Subject(s)
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
12.
Microb Pathog ; 190: 106604, 2024 May.
Article in English | MEDLINE | ID: mdl-38490458

ABSTRACT

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.


Subject(s)
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
13.
Z Naturforsch C J Biosci ; 79(3-4): 89-92, 2024 Mar 25.
Article in English | MEDLINE | ID: mdl-38421614

ABSTRACT

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.


Subject(s)
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
14.
Zhongguo Zhong Yao Za Zhi ; 48(10): 2732-2738, 2023 May.
Article in Chinese | MEDLINE | ID: mdl-37282933

ABSTRACT

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.


Subject(s)
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
15.
Toxins (Basel) ; 14(2)2022 02 15.
Article in English | MEDLINE | ID: mdl-35202169

ABSTRACT

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.


Subject(s)
Antifungal Agents/chemistry , Fusarium/growth & development , Fusarium/metabolism , Mycelium/drug effects , Mycelium/growth & development , Mycotoxins/biosynthesis , Mycotoxins/chemistry , Thymol/chemistry , Transcriptome
16.
Viruses ; 14(2)2022 01 20.
Article in English | MEDLINE | ID: mdl-35215789

ABSTRACT

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.


Subject(s)
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
17.
Int J Mol Sci ; 23(3)2022 Feb 06.
Article in English | MEDLINE | ID: mdl-35163762

ABSTRACT

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.


Subject(s)
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
18.
PLoS One ; 17(1): e0262836, 2022.
Article in English | MEDLINE | ID: mdl-35051224

ABSTRACT

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.


Subject(s)
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
19.
Bioengineered ; 13(2): 3284-3299, 2022 02.
Article in English | MEDLINE | ID: mdl-35100087

ABSTRACT

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.


Subject(s)
Ecosystem , Fungi/growth & development , Models, Biological , Mycelium/growth & development , Wood/microbiology
20.
Molecules ; 27(1)2022 Jan 03.
Article in English | MEDLINE | ID: mdl-35011507

ABSTRACT

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.


Subject(s)
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
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