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1.
Microb Pathog ; 190: 106604, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38490458

RESUMO

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.


Assuntos
Alternaria , Bacillus subtilis , Fungicidas Industriais , Lipopeptídeos , Nitrilas , Doenças das Plantas , Solanum tuberosum , Solanum tuberosum/microbiologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Alternaria/efeitos dos fármacos , Alternaria/crescimento & desenvolvimento , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/crescimento & desenvolvimento , Fungicidas Industriais/farmacologia , Nitrilas/farmacologia , Lipopeptídeos/farmacologia , RNA Ribossômico 16S/genética , Hifas/efeitos dos fármacos , Hifas/crescimento & desenvolvimento , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Peptídeos Cíclicos/farmacologia
2.
Zhongguo Zhong Yao Za Zhi ; 48(10): 2732-2738, 2023 May.
Artigo em Chinês | MEDLINE | ID: mdl-37282933

RESUMO

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.


Assuntos
Alternaria , Caryophyllaceae , Doenças das Plantas , Alternaria/classificação , Alternaria/genética , Alternaria/crescimento & desenvolvimento , Alternaria/patogenicidade , Caryophyllaceae/microbiologia , DNA Fúngico/genética , Micélio/crescimento & desenvolvimento , Filogenia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , China
3.
Toxins (Basel) ; 14(2)2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-35202169

RESUMO

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.


Assuntos
Antifúngicos/química , Fusarium/crescimento & desenvolvimento , Fusarium/metabolismo , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Micotoxinas/biossíntese , Micotoxinas/química , Timol/química , Transcriptoma
4.
Viruses ; 14(2)2022 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-35215789

RESUMO

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.


Assuntos
Bactérias/virologia , Bacteriófagos/fisiologia , Micélio/virologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bacteriófago T4/fisiologia , Micélio/crescimento & desenvolvimento , Pythium/crescimento & desenvolvimento , Pythium/virologia , Microbiologia do Solo
5.
Int J Mol Sci ; 23(3)2022 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-35163762

RESUMO

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.


Assuntos
Proteína Beclina-1/genética , Litchi/crescimento & desenvolvimento , Phytophthora/crescimento & desenvolvimento , Regulação para Cima , Autofagia , Sistemas CRISPR-Cas , Técnicas de Inativação de Genes , Litchi/parasitologia , Micélio/genética , Micélio/crescimento & desenvolvimento , Micélio/patogenicidade , Estresse Oxidativo , Phytophthora/genética , Phytophthora/patogenicidade , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/parasitologia , Reprodução Assexuada , Tolerância ao Sal , Fatores de Virulência/genética
6.
Microbiol Spectr ; 10(1): e0006321, 2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-34985327

RESUMO

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.


Assuntos
Aspergillus fumigatus/química , Aspergillus fumigatus/crescimento & desenvolvimento , Meios de Cultura/metabolismo , Espectrofotometria/métodos , Antifúngicos/farmacologia , Aspergillus fumigatus/efeitos dos fármacos , Aspergillus fumigatus/genética , Parede Celular/genética , Parede Celular/metabolismo , Meios de Cultura/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Glucanos/metabolismo , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Hifas/química , Hifas/efeitos dos fármacos , Hifas/genética , Hifas/crescimento & desenvolvimento , Micélio/química , Micélio/efeitos dos fármacos , Micélio/genética , Micélio/crescimento & desenvolvimento
7.
Molecules ; 27(1)2022 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-35011507

RESUMO

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.


Assuntos
Antioxidantes/química , Inibidores da Colinesterase/química , Misturas Complexas/química , Citotoxinas/química , Ganoderma/química , Micélio/química , Animais , Antioxidantes/farmacologia , Inibidores da Colinesterase/farmacologia , Misturas Complexas/farmacologia , Citotoxinas/farmacologia , Ganoderma/crescimento & desenvolvimento , Melanoma Experimental/metabolismo , Camundongos , Monofenol Mono-Oxigenase/antagonistas & inibidores , Micélio/crescimento & desenvolvimento
8.
Sci Rep ; 12(1): 340, 2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-35013424

RESUMO

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.


Assuntos
Potenciais de Ação/efeitos dos fármacos , Anestésicos Inalatórios/farmacologia , Clorofórmio/farmacologia , Micélio/efeitos dos fármacos , Pleurotus/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Pleurotus/crescimento & desenvolvimento , Fatores de Tempo , Volatilização
9.
Bioengineered ; 13(2): 3284-3299, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35100087

RESUMO

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.


Assuntos
Ecossistema , Fungos/crescimento & desenvolvimento , Modelos Biológicos , Micélio/crescimento & desenvolvimento , Madeira/microbiologia
10.
PLoS One ; 17(1): e0262836, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35051224

RESUMO

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.


Assuntos
Alternaria/efeitos dos fármacos , Antifúngicos/farmacologia , Compostos de Bifenilo/farmacologia , Lauraceae/química , Lignanas/farmacologia , Cebolas/microbiologia , Doenças das Plantas/microbiologia , Extratos Vegetais/farmacologia , Metanol/química , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento
11.
J Toxicol Environ Health A ; 85(2): 43-55, 2022 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-34459359

RESUMO

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.


Assuntos
Antifúngicos/farmacologia , Basidiomycota/química , Agentes de Controle Biológico/farmacologia , Animais , Antifúngicos/química , Ascomicetos/efeitos dos fármacos , Ascomicetos/crescimento & desenvolvimento , Agentes de Controle Biológico/química , Brasil , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Frutas/microbiologia , Germinação/efeitos dos fármacos , Camundongos , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Fenol/análise , Doenças das Plantas/microbiologia , Sementes/crescimento & desenvolvimento , Sementes/microbiologia
12.
Sci Rep ; 11(1): 24157, 2021 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-34921189

RESUMO

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.


Assuntos
Cordyceps , Modelos Biológicos , Micélio , Cordyceps/citologia , Cordyceps/crescimento & desenvolvimento , Micélio/citologia , Micélio/crescimento & desenvolvimento
13.
Sci Rep ; 11(1): 22695, 2021 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-34811424

RESUMO

Animal hosts infected and killed by parasitoid fungi become nutrient-rich cadavers for saprophytes. Bacteria adapted to colonization of parasitoid fungi can be selected and can predominate in the cadavers, actions that consequently impact the fitness of the parasitoid fungi. In Taiwan, the zombie fungus, Ophiocordyceps unilateralis sensu lato (Clavicipitaceae: Hypocreales), was found to parasitize eight ant species, with preference for a principal host, Polyrhachis moesta. In this study, ant cadavers grew a fungal stroma that was predominated by Bacillus cereus/thuringiensis. The bacterial diversity in the principal ant host was found to be lower than the bacterial diversity in alternative hosts, a situation that might enhance the impact of B. cereus/thuringiensis on the sympatric fungus. The B. cereus/thuringiensis isolates from fungal stroma displayed higher resistance to a specific naphthoquinone (plumbagin) than sympatric bacteria from the environment. Naphthoquinones are known to be produced by O. unilateralis s. l., and hence the resistance displayed by B. cereus/thuringiensis isolates to these compounds suggests an advantage to B. cereus/thuringiensis to grow in the ant cadaver. Bacteria proliferating in the ant cadaver inevitably compete for resources with the fungus. However, the B. cereus/thuringiensis isolates displayed in vitro capabilities of hemolysis, production of hydrolytic enzymes, and antagonistic effects to co-cultured nematodes and entomopathogenic fungi. Thus, co-infection with B. cereus/thuringiensis offers potential benefits to the zombie fungus in killing the host under favorable conditions for reproduction, digesting the host tissue, and protecting the cadaver from being taken over by other consumers. With these potential benefits, the synergistic effect of B. cereus/thuringiensis on O. unilateralis infection is noteworthy given the competitive relationship of these two organisms sharing the same resource.


Assuntos
Formigas/microbiologia , Bacillus cereus/genética , Bacillus cereus/metabolismo , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Cadáver , Hypocreales/metabolismo , Animais , Formigas/classificação , Bacillus cereus/isolamento & purificação , Bacillus thuringiensis/isolamento & purificação , Biodiversidade , Caenorhabditis elegans/microbiologia , Técnicas de Cocultura , Coinfecção , DNA Bacteriano/genética , Florestas , Especificidade de Hospedeiro , Micélio/crescimento & desenvolvimento , Micélio/metabolismo , Filogenia , Especificidade da Espécie , Simpatria , Taiwan
14.
PLoS One ; 16(11): e0260170, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34847161

RESUMO

The transition from a linear to a circular economy is urgently needed to mitigate environmental impacts and loss of biodiversity. Among the many potential solutions, the development of entirely natural-based materials derived from waste is promising. One such material is mycelium-bound composites obtained from the growth of fungi onto solid lignocellulosic substrates, which find applications such as insulating foams, textiles, packaging, etc. During growth, the fungus degrades and digests the substrate to create a web-like stiff network called mycelium. The development of the mycelium is influenced by several factors, including the substrate composition. As food waste accounts for nearly 44% of total municipal solid waste, incorporating food in the substrate composition could be a means to increase the nutrients absorbed by the fungus. In this paper, we study the effects of the addition of food supplements on the growth of two fungal species, Ganoderma lucidum and Pleurotus ostreatus. The substrates, the food supplements, and the mycelia are characterized using Fourier-transform infrared spectroscopy, scanning electron microscopy, and optical microscopy. Our results show that addition of barley as a supplement significantly boosts the growth of G. lucidum and P. ostreatus. Using a common food as a nutritious enrichment for the development of mycelium is a simple and straightforward strategy to create waste-based mycelium-bound biocomposites for a large range of applications, on-site, therefore promoting a circular economy.


Assuntos
Alimentos , Micélio/crescimento & desenvolvimento , Pleurotus/crescimento & desenvolvimento , Eliminação de Resíduos , Reishi/crescimento & desenvolvimento
15.
BMC Microbiol ; 21(1): 318, 2021 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-34784888

RESUMO

BACKGROUND: Solid-state fermentation is a fungal culture technique used to produce compounds and products of industrial interest. The growth behaviour of filamentous fungi on solid media is challenging to study due to the intermixity of the substrate and the growing organism. Several strategies are available to measure indirectly the fungal biomass during the fermentation such as following the biochemical production of mycelium-specific components or microscopic observation. The microscopic observation of the development of the mycelium, on lignocellulosic substrate, has not been reported. In this study, we set up an experimental protocol based on microscopy and image processing through which we investigated the growth pattern of Phanerochaete chrysosporium on different Miscanthus x giganteus biomass fractions. RESULTS: Object coalescence, the occupied surface area, and radial expansion of the colony were measured in time. The substrate was sterilized by autoclaving, which could be considered a type of pre-treatment. The fastest growth rate was measured on the unfractionated biomass, followed by the soluble fraction of the biomass, then the residual solid fractions. The growth rate on the different fractions of the substrate was additive, suggesting that both the solid and soluble fractions were used by the fungus. Based on the FTIR analysis, there were differences in composition between the solid and soluble fractions of the substrate, but the main components for growth were always present. We propose using this novel method for measuring the very initial fungal growth by following the variation of the number of objects over time. Once growth is established, the growth can be followed by measurement of the occupied surface by the mycelium. CONCLUSION: Our data showed that the growth was affected from the very beginning by the nature of the substrate. The most extensive colonization of the surface was observed with the unfractionated substrate containing both soluble and solid components. The methodology was practical and may be applied to investigate the growth of other fungi, including the influence of environmental parameters on the fungal growth.


Assuntos
Phanerochaete/crescimento & desenvolvimento , Biomassa , Fermentação , Cinética , Micélio/crescimento & desenvolvimento , Micélio/metabolismo , Phanerochaete/química , Phanerochaete/metabolismo , Poaceae/crescimento & desenvolvimento , Poaceae/metabolismo
16.
Molecules ; 26(22)2021 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-34834000

RESUMO

Enniatins are mycotoxins produced by Fusarium species contaminating cereals and various agricultural commodities. The co-occurrence of these mycotoxins in large quantities with other mycotoxins such as trichothecenes and the possible synergies in toxicity could lead to serious food safety problems. Using the agar dilution method, Ammoides pusilla was selected among eight Tunisian plants for the antifungal potential of its essential oil (EO) on Fusarium avenaceum mycelial growth and its production of enniatins. Two EO batches were produced and analyzed by GC/MS-MS. Their activities were measured using both contact assays and fumigant tests (estimated IC50 were 0.1 µL·mL-1 and 7.6 µL·L-1, respectively). The A. pusilla EOs and their volatiles inhibited the germination of spores and the mycelial growth, showing a fungistatic but not fungicidal activity. The accumulation of enniatins was also significantly reduced (estimated IC50 were 0.05 µL·mL-1 for the contact assays and 4.2 µL·L-1 for the fumigation assays). The most active batch of EO was richer in thymol, the main volatile compound found. Thymol used as fumigant showed a potent fungistatic activity but not a significant antimycotoxigenic activity. Overall, our data demonstrated the bioactivity of A. pusilla EO and its high potential to control F. avenaceum and its enniatins production in agricultural commodities.


Assuntos
Apiaceae/química , Depsipeptídeos/biossíntese , Fusarium/crescimento & desenvolvimento , Micélio/crescimento & desenvolvimento , Micotoxinas/biossíntese , Óleos Voláteis , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Timol/química , Timol/farmacologia
17.
Int J Biol Macromol ; 192: 210-218, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34619278

RESUMO

Schizophyllum commune (S. commune) polysaccharides are biomacromolecules with multiple biological activities and wide applications. In this study, polysaccharide production through submerged fermentation of S. commune using different surfactants was investigated. The addition of 1 g/L of polyoxyethylene sorbitan monooleate (Tween 80) at the beginning of the fermentation showed the best promotional effects on collective exopolysaccharide (EPS) production (which increased by 37.17%) while shortening the production cycle by 2 days. The monosaccharide composition of the EPS produced when the added Tween 80 was similar to that of the control; however, the molecular weight (Mw) was lower. Notably, the addition of Tween 80 significantly increased the ATP levels and the transcription levels of phosphoglucomutase and ß-glucan synthase genes in the polysaccharide synthesis pathway. The addition of Tween 80 reduced the pellet size of the mycelium compared to that of the control, but did not significantly change the microstructure of the mycelial cells. This study proposes an efficient strategy for the production of polysaccharides through submerged fermentation of S. commune, and elucidates the detailed mechanism of using Tween 80 as a fermentation stimulatory reagent.


Assuntos
Fermentação , Polissacarídeos/biossíntese , Schizophyllum/efeitos dos fármacos , Schizophyllum/metabolismo , Tensoativos/farmacologia , Trifosfato de Adenosina/metabolismo , Técnicas de Cultura Celular por Lotes , Biomassa , Membrana Celular/metabolismo , Parede Celular/química , Relação Dose-Resposta a Droga , Glucose/metabolismo , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Micélio/metabolismo , Permeabilidade , Polissorbatos/metabolismo , Polissorbatos/farmacologia , Tensoativos/metabolismo
18.
World J Microbiol Biotechnol ; 37(12): 203, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34669053

RESUMO

White mold disease, caused by the phytopathogen Sclerotinia sclerotiorum, provokes severe productivity losses in several economically important crops. Biocontrol agents, especially antagonist filamentous fungi, are environmentally friendly alternatives to the chemical fungicides used in white mold management. The objective of this study was to screen for basidiomycete fungi capable of inhibiting S. sclerotiorum and investigate their bioactive metabolites responsible for antifungal activities. Two out of 17 tested basidiomycete isolates inhibited the mycelial growth of S. sclerotiorum in pair culture experiments on agar plates, namely Oudemansiella canarii BRM-044600 and Laetisaria arvalis ATCC52088. O. canarii BRM-044600 liquid culture filtrate exhibited the greatest antifungal activity and was selected for further investigation. UHPLC-MS analysis suggests that six putative strobilurins, including strobilurin A and/or stereoisomers of this compound (m/z 259.1299, [M + H]+) and three putative strobilurins with m/z 257.1184 ([M + H]+) are likely responsible for the antifungal activity observed in the culture filtrate. For the first time, this work demonstrated the potential of O. canarii for white mold biocontrol and strobilurin production.


Assuntos
Agaricales/metabolismo , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Ascomicetos/efeitos dos fármacos , Metabolismo Secundário , Basidiomycota , Agentes de Controle Biológico/farmacologia , Ácidos Graxos Insaturados/metabolismo , Fungicidas Industriais/farmacologia , Testes de Sensibilidade Microbiana , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Doenças das Plantas/microbiologia , Estereoisomerismo , Estrobilurinas/metabolismo
19.
Pak J Biol Sci ; 24(3): 374-382, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34486323

RESUMO

<b>Background and Objective:</b> <i>Trametes versicolor</i> has not only been valued in medical use but also in environmental protection. One of the major challenges currently faced in the commercial cultivation of <i>T. versicolor</i> is finding superior strains that can produce high yields. In an attempt to search for high-yield potential <i>T. versicolor</i>, two wild strains, namely VNUA and BV, were isolated and evaluated for potential cultivation. <b>Materials and Methods:</b> Optimized culture conditions were set up by one-individual factor-at-a-time. Four different kinds of culture media, including Czapek, Raper, PGA and modified Potato Dextrose Agar (PDA), were investigated to ascertain the optimal media. The efficiency of sawdust and rice grain for mother spawn production was evaluated. Different combinations of sawdust and rice husk were tested to investigate the most favorable substrate mixtures. <b>Results:</b> The ideal medium and temperature for the favorable mycelial growth of <i>T. versicolor</i> were PGA and 30°C, respectively. The optimal spawning material for upscaling of the mycelium was Treatment D (20% rice grain, 79% sawdust and 1% calcium carbonate). The strains were successfully cultivated in a basal substrate combination of sawdust and rice husk supplemented with wheat bran. Investigated strains responded differently to different substrates cultivation. Of note, compared with strain BV, strain VNUA showed a significantly higher biological efficiency (7.3%). <b>Conclusion:</b> Wild <i>T. versicolor</i> strains were successfully fructified under artificial cultivation conditions. Strain VNUA can be considered as a potential strain for commercial cultivation. The use of sawdust for the spawn production of <i>T. versicolor</i> can reduce the cost of manufacturing.


Assuntos
Polyporaceae/isolamento & purificação , Especificidade por Substrato , Madeira/análise , Micélio/crescimento & desenvolvimento , Vietnã
20.
Gene ; 802: 145863, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34358628

RESUMO

Hydrophobins are small, secreted proteins with important physiological functions in mycelial growth and fungal development. Here, 1 nucleus-specific and 35 allelic hydrophobin genes were identified in the genome of a white rot fungus, Coriolopsis trogii. Among these, 22 were eight-cysteine class I hydrophobin genes and the other 14 were uncommon six-cysteine hydrophobin genes. The six-cysteine hydrophobins were speculated to have originated from a common ancestor. The hydrophobin genes favored a clustering distribution and two recent duplication pairs were identified. The genes had conserved gene structures with three exons and two introns. Cthyd18, Cthyd19, and Cthyd32 were constitutively highly expressed in all developmental stages. Cthyd20, Cthyd21, Cthyd22, Cthyd28, Cthyd30, Cthyd31, and Cthyd33 were highly expressed in mycelia, and Cthyd12 and Cthyd35 in the reproductive stages. Sixteen hydrophobin genes were regulated differently in the transition from mycelia to primordia; Cthyd35 showed maximal upregulation of 1922-fold, and Cthyd23 showed maximal downregulation of 552-fold. Most (32) hydrophobin genes showed significant differential expression between mycelia cultured in different media (potato dextrose agar or broth). Weighted gene co-expression network analysis and promoter analysis revealed that C2H2 zinc finger proteins may regulate hydrophobin genes. These results may support further research into the function and evolution of hydrophobins.


Assuntos
Proteínas Fúngicas/genética , Polyporaceae/genética , Regulação Fúngica da Expressão Gênica , Genoma Fúngico , Micélio/genética , Micélio/crescimento & desenvolvimento , Polyporaceae/crescimento & desenvolvimento , RNA-Seq , Reação em Cadeia da Polimerase em Tempo Real
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