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1.
Chemosphere ; 253: 126731, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32302907

RESUMO

Bioremediation of Cr(VI) contamination using microorganisms is a promising method for reducing its environmental risks. The objective of this study was to clarify Cr(VI) removal by Penicillium oxalicum SL2 in terms of indirect Cr(VI) reduction by metabolites, interaction sites, and form transformation of chromium. Strain SL2 could sequentially remove Cr(VI) in the bioreactor. Oxalic acid produced by the fungus contributed to Cr(VI) reduction. Scanning transmissiony X-ray microscop (STXM) analysis suggested strain SL2 could partly reduce Cr(VI) to Cr(III) in the cell. Amine, carboxyl, and phosphate groups were related to Cr(VI) removal. Chromium K-edge X-ray absorption near edge structure (XANES) analysis implied Cr(III)-Cys potentially acted as an intermediate for the formation of chromium oxalate complexes during the process of treatment. This study would support the application of strain SL2 in Cr(VI) bioremediation and expand knowledge on the interaction of chromium with fungus.


Assuntos
Reatores Biológicos/microbiologia , Cromo/análise , Poluentes Ambientais/análise , Micélio/metabolismo , Ácido Oxálico/análise , Penicillium/metabolismo , Biodegradação Ambiental , Cromo/metabolismo , Poluentes Ambientais/metabolismo , Ácido Oxálico/metabolismo , Oxirredução , Fosfatos/análise
2.
Ecotoxicol Environ Saf ; 194: 110383, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32143105

RESUMO

Strains of Trichoderma harzianum are well-known producers of bioactive secondary metabolites and have a beneficial effect on plants. However, to the best of our knowledge, the effect of the commonly used pesticides on the activity of this fungus is not yet investigated. Therefore, in the present study, the effect of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) on the lipidome and selected extracellular compounds synthesized by T. harzianum IM 0961 was examined. It was observed that the herbicide 2,4-D caused changes in the lipid composition of the mycelium and that the herbicide exhibited lipophilic properties. In addition, the herbicide disturbed the phosphatidylcholine (PC)/phosphatidylethanolamine (PE) ratio and increased membrane permeability. The higher amount of cardiolipin CL 72:7 and the lower amount of CL 72:8 could have been associated with a decreased ratio of 18:2 and 18:1 fatty acids in the herbicide-treated samples. Moreover, in the presence of 2,4-D, an increased lipid peroxidation (twofold), as well as a higher content of oxylipin (9-HODE and 13-HODE) and phosphatidic acid (PA), was noted, confirming that 2,4-D induced lipid peroxidation in the mycelium. The herbicide also exerted its toxic effect on the production of 14-aminoacid peptaibols and two compounds, harzianic acid and t22-azaphilone, exhibiting antibiotic and plant growth-promoting activity. During proteomic analysis, the synthesis of some proteins, such as calcineurin-like phosphoesterase metallophosphatases (MPPs), which modulate the properties of cell walls, was found to be inhibited by the herbicide. These presented findings may be of significant value in understanding the effect of 2,4-D on the activity of T. harzianum.


Assuntos
Ácido 2,4-Diclorofenoxiacético/toxicidade , Proteínas Fúngicas/metabolismo , Herbicidas/toxicidade , Metabolismo dos Lipídeos/efeitos dos fármacos , Desenvolvimento Vegetal/efeitos dos fármacos , Reguladores de Crescimento de Planta , Trichoderma/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Micélio/efeitos dos fármacos , Micélio/metabolismo , Oxilipinas/metabolismo , Peptaibols/metabolismo , Fosfolipídeos/metabolismo , Proteômica , Trichoderma/metabolismo
3.
Carbohydr Polym ; 232: 115766, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31952583

RESUMO

Type 2 diabetes mellitus plagues many people in China and the world, and its nephritis complication is the leading cause of death for patients. Paecilomyces hepiali contained various functional components, especially polysaccharides, which possesses well pharmacological activities. In this study, polysaccharide purified from Paecilomyces hepiali fermented mycelium entitled PHEA was obtained, and its structure was systemically characterized using fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR). In C57BL/KsJ (BKS).Cg-Dock7m +/+ Leprdb/JNju mice (db/db mice), via detecting the alternations on biochemical criterions, pathological indicators and protein expressions related to nuclear factor-E2-related factor 2 (Nrf2) and nuclear factor-κB (NF-κB) signaling in serum and/or tissues including muscle, liver and kidney after 8-week PHEA administration, the hypoglycemic, hypolipidemic, and anti-diabetic nephropathic activities of PHEA were confirmed. The purified P. Hepiali polysaccharide with the anti-diabetic and -nephritic properties was first reported in this study via regulating Nrf2-meadited NF-κB signaling in db/db mice.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Nefropatias Diabéticas/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Micélio/química , Polissacarídeos/uso terapêutico , Animais , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Nefropatias Diabéticas/metabolismo , Modelos Animais de Doenças , Fermentação , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Micélio/metabolismo , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Tamanho da Partícula , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Transdução de Sinais/efeitos dos fármacos , Propriedades de Superfície
4.
J Microbiol ; 58(1): 39-45, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31686390

RESUMO

A lectin gene (plectin) with a high level of expression was previously identified by comparative transcriptome analysis of Pleurotus ostreatus. In this study, we cloned a 733-bp DNA fragment from the start codon of the plectin gene. Sequence analysis showed that the plectin promoter (Plp) region contained several eukaryotic transcription factor binding motifs, such as the TATA-box, four possible CAAT-box, light respon-siveness motifs and MeJA-responsiveness motifs. To deter-mine whether the Plp promoter was a light-regulated promoter, we constructed an expression vector with the fused egfp-hph fragment under the control of the Plp promoter and transformed P. ostreatus mycelia via Agrobacterium tunte-faciens. PCR and Southern blot analyses confirmed the Plp-egfp-hph fragment was integrated into the chromosomal DNA of transformants. qRT-PCR, egfp visualization, and intracellular egfp determination experiments showed the Plp promoter could be a light-induced promoter that may be suitable for P. ostreatus genetic engineering. This study lays the foundation for gene homologous expression in P. ostreatus.


Assuntos
Proteínas Fúngicas , Engenharia Genética/métodos , Lectinas , Pleurotus , Proteínas Recombinantes , Agrobacterium tumefaciens/genética , Clonagem Molecular , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Proteínas de Fluorescência Verde/genética , Lectinas/genética , Lectinas/metabolismo , Micélio/metabolismo , Pleurotus/genética , Pleurotus/metabolismo , Regiões Promotoras Genéticas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
5.
FEMS Microbiol Ecol ; 96(2)2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31868883

RESUMO

Understanding the post-senescent fate of fungal mycelium is critical to accurately quantifying forest carbon and nutrient cycling, but how this organic matter source decomposes in wood remains poorly studied. In this study, we compared the decomposition of dead fungal biomass (a.k.a. necromass) of two species, Mortierella elongata and Meliniomyces bicolor, in paired wood and soil plots in a boreal forest in northern Minnesota, USA. Mass loss was quantified at four time points over an 8-week incubation and the richness and composition of the fungal communities colonizing fungal necromass were characterized using high-throughput sequencing. We found that the structure of fungal decomposer communities in wood and soil differed, but, in both habitats, there was relatively rapid decay (∼30% remaining after 56 days). Mass loss was significantly faster in soil and for high-quality (i.e. high nitrogen and low melanin) fungal necromass. In both habitats, there was a clear trajectory of early colonization by opportunistic fungal taxa followed by colonization of fungi with greater enzymatic capacities to degrade more recalcitrant compounds, including white-rot and ectomycorrhizal fungi. Collectively, our results indicate that patterns emerging regarding substrate quality effects on fungal necromass decomposition in soil and leaf litter can be largely extended to fungal necromass decomposition in wood.


Assuntos
Micélio/metabolismo , Micobioma/fisiologia , Microbiologia do Solo , Madeira/microbiologia , Biomassa , Carbono/análise , Carbono/metabolismo , Fungos/classificação , Fungos/crescimento & desenvolvimento , Fungos/metabolismo , Micélio/química , Nitrogênio/análise , Nitrogênio/metabolismo , Solo/química , Taiga , Madeira/química
6.
J Sci Food Agric ; 100(1): 441-446, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31512241

RESUMO

BACKGROUND: The production of mycelium from endophytic fungi is of interest for applications ranging from inoculants and biofertilizers for crop production to fermentations for enzyme and metabolite production. The purpose of this study was to test the capacity of a solid growth medium based on beet pulp for growing different strains of endophytes. RESULTS: The ergosterol content of inoculated medium was measured to estimate fungal growth. Several parameters related to the preparation of the growth medium, such as water content, calcium salts and incubation time, were evaluated. The greatest fungal biomass production was observed in a medium prepared with a 1:2 (beet pulp:water) ratio, containing calcium sulfate and carbonate. Strains belonging to different fungal species grew well in the growth medium finally selected, producing yields ranging from 50 to 500 g mycelium per kilogram of dry culture, after 22-27 days. Cultures containing up to 400 g beet pulp grew successfully, and could be scaled up. CONCLUSION: A solid culture medium based on beet pulp supported the growth of diverse taxa of fungal endophytes. Both the water and calcium salt content of the growth medium affected the efficiency of mycelium production. Considering these factors, beet pulp medium was an excellent endophyte cultivation medium because of the high yield of fungal biomass observed, together with its ease of handling and scaling-up production. © 2019 Society of Chemical Industry.


Assuntos
Beta vulgaris/microbiologia , Meios de Cultura/metabolismo , Endófitos/crescimento & desenvolvimento , Fungos/crescimento & desenvolvimento , Beta vulgaris/química , Biomassa , Meios de Cultura/química , Endófitos/metabolismo , Fermentação , Fungos/metabolismo , Micélio/crescimento & desenvolvimento , Micélio/metabolismo
7.
J Sci Food Agric ; 100(2): 803-810, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31612503

RESUMO

BACKGROUND: New evidence has shown that arbuscular mycorrhizal (AM) fungi can contribute to the aluminum (Al3+ ) tolerance of host plants growing in acidic soils with phytotoxic levels of Al3+ . The aim of this study was to investigate the role of AM fungi isolated from naturally occurring Al3+ acidic soils in conferring host tolerance to Al3+ toxicity in three wheat cultivars differing in Al3+ sensitivity. The experiment was conducted in a soilless substrate (vermiculite/perlite, 2:1 v/v) using two Al3+ -tolerant wheat genotypes and one Al3+ -sensitive wheat genotype. The wheat was colonized with a consortium of AM fungi isolated from an Andisol, with or without Al3+ at a concentration of 200 µmol L-1 . RESULTS: The response of wheat to Al3+ in the medium was dependent on both the plant genotype and AM colonization. The benefits of the AM fungi to the wheat cultivars included an increased P concentration and relatively low Al3+ accumulation in the plants. This was achieved through two mechanisms. First, the metal-chelating capacity of the AM fungi was clear in two of the cultivars ('Tukan' and 'Porfiado'), in which the enhanced extraradical mycelium development was able to retain Al3+ in the glomalin and hyphae. Second, the increased AM-induced acid phosphatase activity in the rhizosphere of the other cultivar ('Atlas 66') increased host nutrition possibly by hyphae-mediated nutrient uptake and glomalin-related soil protein. CONCLUSION: The results suggest that the role of AM fungi in cultivar-specific Al3+ detoxification can be achieved by increased extraradical mycelial filters and enhanced bioavailability of P in the host rhizosphere. © 2019 Society of Chemical Industry.


Assuntos
Alumínio/metabolismo , Micorrizas/metabolismo , Fósforo/metabolismo , Poluentes do Solo/metabolismo , Triticum/microbiologia , Alumínio/análise , Alumínio/toxicidade , Hifas/crescimento & desenvolvimento , Hifas/metabolismo , Micélio/crescimento & desenvolvimento , Micélio/metabolismo , Micorrizas/crescimento & desenvolvimento , Fósforo/análise , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
8.
J Sci Food Agric ; 100(2): 744-754, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31637724

RESUMO

BACKGROUND: The application of chemical fungicides is currently the main method for the control of postharvest decay of fruits and vegetables. However, public concern has been growing towards the effect of fungicides on food safety, human health and environmental pollution. Thus, interest in microbial biocontrol agent development has grown, such agents being considered both safe and environmentally friendly. Pseudomonas fluorescens is widely distributed in nature, and one of the most valuable biocontrol and plant growth-promoting rhizobacteria. In this study, the efficacy and the potential associated modes of action of P. fluorescens ZX against Penicillium italicum on oranges (Citrus sinensis Osbeck) were investigated. RESULTS: The application of P. fluorescens ZX significantly reduced blue mold lesion size and incidence in comparison to the control, where P. fluorescens ZX was effective when applied preventatively but not curatively. In dual cultures, treatment with cell-free autoclaved cultures or culture filtrate had a limited capacity to suppress P. italicum, while P. italicum was inhibited by bacterial fluid and bacterial suspension with living cells in vitro. The P. fluorescens ZX isolate displayed protease, but not chitinase, glucanase or cellulose, activity, and produced siderophores and volatile organic compounds with antifungal abilities. Competition tests showed P. fluorescens ZX could use fructose, sucrose, aspartic acid, threonine, serine, glycine, valine, lysine and proline better than P. italicum. Furthermore, an effective biofilm that peaked after a 24-hour incubation at 30 °C was formed by the P. fluorescens ZX isolate. Light microscopy and scanning electron microscopy observations indicate the P. fluorescens ZX isolate could not undergo direct parasitism or hyperparasitism. CONCLUSIONS: Competition for nutrients and niches, biofilm formation, inhibition of spore germination and mycelial growth, and production of inhibitory metabolites may play important roles in P. fluorescens ZX antagonism of P. italicum. © 2019 Society of Chemical Industry.


Assuntos
Antibiose , Citrus/microbiologia , Pseudomonas fluorescens/fisiologia , Biofilmes , Frutas/microbiologia , Micélio/crescimento & desenvolvimento , Micélio/metabolismo , Penicillium/crescimento & desenvolvimento , Penicillium/metabolismo , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle
9.
Int J Mol Sci ; 21(1)2019 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-31881712

RESUMO

Depression is a common and severe neuropsychiatric disorder that is one of the leading causes of global disease burden. Although various anti-depressants are currently available, their efficacies are barely adequate and many have side effects. Hericium erinaceus, also known as Lion's mane mushroom, has been shown to have various health benefits, including antioxidative, antidiabetic, anticancer, anti-inflammatory, antimicrobial, antihyperglycemic, and hypolipidemic effects. It has been used to treat cognitive impairment, Parkinson's disease, and Alzheimer's disease. Bioactive compounds extracted from the mycelia and fruiting bodies of H. erinaceus have been found to promote the expression of neurotrophic factors that are associated with cell proliferation such as nerve growth factors. Although antidepressant effects of H. erinaceus have not been validated and compared to the conventional antidepressants, based on the neurotrophic and neurogenic pathophysiology of depression, H. erinaceus may be a potential alternative medicine for the treatment of depression. This article critically reviews the current literature on the potential benefits of H. erinaceus as a treatment for depressive disorder as well as its mechanisms underlying the antidepressant-like activities.


Assuntos
Basidiomycota/química , Produtos Biológicos/uso terapêutico , Transtorno Depressivo/tratamento farmacológico , Basidiomycota/metabolismo , Produtos Biológicos/química , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Ensaios Clínicos como Assunto , Transtorno Depressivo/patologia , Diterpenos/química , Diterpenos/isolamento & purificação , Diterpenos/uso terapêutico , Humanos , Indóis/química , Indóis/isolamento & purificação , Indóis/uso terapêutico , Micélio/química , Micélio/metabolismo , Fatores de Crescimento Neural/metabolismo
10.
Molecules ; 24(19)2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31569709

RESUMO

Hericium erinaceus is a medicinal mushroom that contains many molecules promising a plethora of therapeutic properties. In this study, the strain H.e.2 (MicUNIPV, University of Pavia, Italy) was isolated from a sporophore collected in Tuscany (Italy). Mycelium, primordium, and wild type and cultivated sporophores were analyzed by HPLC-UV-ESI/MS. Erinacine A in the mycelium and hericenones C and D in the sporophores were quantified by comparison with their standard molecules. For the first time, H. erinaceus primordium was also investigated for the presence of these molecules. Comparing with the literature data, hericenes, molecules structurally similar to hericenones, were present in all our samples. The highest contents of hericenones C and D were detected in cultivated sporophores, compared to the wild type. The comparison of these data with those of another Italian H. erinaceus strain (H.e.1 MicUNIPV) was discussed. The results led us to select H. erinaceus strains more suitable for mycelium production or sporophore cultivation to obtain extracts with a higher content of bioactive compounds. This work provides a further step towards standardizing the procedures in the development of dietary supplements made from mushrooms.


Assuntos
Agaricales/metabolismo , Metaboloma , Metabolômica , Micélio/metabolismo , Esporos Fúngicos/metabolismo , Agaricales/química , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Metabolômica/métodos , Estrutura Molecular , Micélio/química , Esporos Fúngicos/química
11.
Appl Microbiol Biotechnol ; 103(21-22): 8923-8935, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31520132

RESUMO

UV and gamma irradiation mutagenesis was applied on Aspergillus fumigatus and Alternaria tenuissima in order to improve their producing ability of paclitaxel. Among the screened mutants, two stable strains (designated TXD105-GM6 and TER995-GM3) showed the maximum paclitaxel production. Paclitaxel titers of the two respective mutants were dramatically intensified to 1.22- and 1.24-fold, as compared by their respective parents. Immobilization using five different entrapment carriers of calcium alginate, agar-agar, Na-CMC, gelatin, and Arabic gum was successfully applied for production enhancement of paclitaxel by the two mutants. The immobilized cultures were superior to free-cell cultures and paclitaxel production by the immobilized mycelia was much higher than that of the immobilized spores using all the tried carriers. Moreover, calcium alginate gel beads were found the most conductive and proper entrapment carrier for maximum production of paclitaxel. The feasibility of the paclitaxel production by the immobilized mycelia as affected by incubation period, medium volume, and number of beads per flask was adopted. Under the favorable immobilization conditions, the paclitaxel titers were significantly intensified to 1.31- and 1.88-fold by the respective mutants, as compared by their free cultures. The obtained paclitaxel titers by the immobilized mycelia of the respective mutants (694.67 and 388.65 µg L-1) were found promising in terms of fungal production of paclitaxel. Hence, these findings indicate the future possibility to reduce the cost of producing paclitaxel and suggest application of the immobilization technique for the biotechnological production of paclitaxel at an industrial scale.


Assuntos
Alternaria/metabolismo , Antineoplásicos/metabolismo , Aspergillus fumigatus/metabolismo , Paclitaxel/biossíntese , Alginatos/química , Alternaria/química , Alternaria/genética , Aspergillus fumigatus/química , Aspergillus fumigatus/genética , Células Imobilizadas/química , Células Imobilizadas/metabolismo , Fermentação , Microbiologia Industrial , Micélio/química , Micélio/genética , Micélio/metabolismo
12.
Microbiol Res ; 228: 126299, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31422231

RESUMO

Wastewaters from textile dyeing industries represent an ecological concern, notably due to the known toxicity of azo dyes to the local microbiome and human health. Although physicochemical approaches are the rule for the treatment of industrial effluents, biological strategies such as enzyme-mediated dye destaining is a promising alternative. Notwithstanding a broad range of microorganisms, including fungi, algae, yeast, and bacteria, display dye-destaining properties, most of the literature has focused in ligninolytic fungi, leaving other classes of organisms somehow ignored. In this study, six endophytic strains isolated from Maytenus ilicifolia were studied for their destaining activity. The phylogenetic and morphological analysis allowed the identification of strain LGMF1504 as Neopestalotiopsis sp. LGMF1504 that decolorized several commercial dyes as the result of a mycelium-associated laccase. The enzyme expression was modulated by carbon and nitrogen content in the culture medium, it was weakly affected by the presence of aromatic compounds and metal ions while some common laccase mediators improved the destaining activity onto dye substrates. The best culture condition observed for laccase activity was a basic culture medium containing 5 g L-1 starch and 15 g L-1 ammonium tartrate. The laccase activity showed low substrate specificity and almost unaltered performance in a wide range of pH values and NaCl concentrations, suggesting the potential of Neopestalotiopsis sp. LGMF1504 for biodegradation approaches.


Assuntos
Corantes/metabolismo , Endófitos/metabolismo , Lacase/metabolismo , Micélio/metabolismo , Compostos Azo/toxicidade , Biodegradação Ambiental , Carbono , Corantes/toxicidade , DNA Fúngico , Endófitos/classificação , Endófitos/isolamento & purificação , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Fungos/metabolismo , Concentração de Íons de Hidrogênio , Metais , Tipagem de Sequências Multilocus , Nitrogênio , Filogenia , Cloreto de Sódio/análise , Indústria Têxtil , Águas Residuárias
13.
Appl Microbiol Biotechnol ; 103(19): 7883-7889, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31440792

RESUMO

Glucosamine (GlcN) is an amine sugar, in which a hydroxyl group of glucose is replaced with an amino group. It is an important part of the polysaccharides chitin and chitosan and is highly hydrophilic. It is also an important compound required for the formation of cartilage cells and represents one of the elementary units of the cartilage matrix and joint fluid. GlcN has been widely used in food, cosmetics, health care, and pharmaceutical industries. This paper fully addresses the categories and biomanufacturing methods of GlcN, including its production by fermentation with wild-type as well as engineered microorganisms and enzymatic catalysis with a series of chitinolytic enzymes. However, GlcN is usually produced from glucose by fermentation in a coupled manner with N-acetylglucosamine (GlcNAc). Enzymatic catalysis is thus a specific pathway for production of GlcN where chitin can be directly hydrolyzed to GlcN. In industry, GlcN produced with fungal mycelium as raw materials (plant GlcN) is thought as a high-end product because of vegetarian and non-transgenosis. In our opinion, more studies should be performed in order to develop a competitive enzymatic pathway using Aspergillus niger mycelium for the preparation of high-end GlcN.


Assuntos
Aspergillus niger/metabolismo , Biocatálise , Glucosamina/metabolismo , Redes e Vias Metabólicas , Fermentação , Glucosamina/isolamento & purificação , Microbiologia Industrial/métodos , Micélio/metabolismo
14.
Folia Microbiol (Praha) ; 64(6): 835-844, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31372834

RESUMO

Homeostatic mechanisms preventing the toxicity of heavy metal ions in cells involve, among others, compartmentalization and binding with peptidaceous ligands, particularly the cysteinyl-rich metallothioneins (MTs). We have previously shown that in natural conditions Zn-overaccumulating ectomycorrhizal (EM) fungus Russula bresadolae stores nearly 40% of Zn bound with cysteinyl- and hystidyl-containing RaZBP peptides, which resemble MTs, while the detoxification of Zn and Cd in EM Hebeloma mesophaeum relies upon compartmentalization in small vesicles and vacuoles, respectively. Here, we examined the performance of RaZBP1 gene expressed in H. mesophaeum mycelium with respect to handling of Zn and Cd. Expression of RaZBP1 impaired growth of the mycelium on low-Zn medium by 60%, the growth was partly ameliorated upon the addition of Zn and remained considerable up to 2 mmol/L Zn, while the growth of the wild-type and control mycelia transformed with empty T-DNA was severely reduced in the presence of 0.5 mmol/L Zn; furthermore, RaZBP1 slightly added to Cd tolerance in the range of Cd concentrations of 0.625 to 8 µmol/L. Staining of Zn- or Cd-exposed hyphal cells with Zn- or Cd-specific fluorescent tracers did not indicate that the expression of RaZBP1 would redirect the flow of the metals away from their innate sinks. Size exclusion chromatography of extracted metal species revealed that the complexes corresponding to Zn/Cd-RaZBP1 are present only in minute levels. Considering that RaZBP1 inhibited growth at low Zn, and despite the benefit that it provided to H. mesophaeum in the presence of high Zn and moderate Cd, these data indicate that the binding of excess Zn and Cd with RaZBP1 is not a trait that would be outright transmitted to H. mesophaeum.


Assuntos
Cádmio/metabolismo , Proteínas Fúngicas/metabolismo , Hebeloma/metabolismo , Metalotioneína/metabolismo , Zinco/metabolismo , Basidiomycota/genética , Vesículas Citoplasmáticas/metabolismo , Proteínas Fúngicas/genética , Hebeloma/genética , Hebeloma/crescimento & desenvolvimento , Metalotioneína/genética , Micélio/genética , Micélio/crescimento & desenvolvimento , Micélio/metabolismo , Micorrizas/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
15.
Ecotoxicol Environ Saf ; 183: 109503, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31394376

RESUMO

Sclerotinia sclerotiorum (S. sclerotiorum) is a devastating fungal pathogen with worldwide distribution, and threatened the agro-ecological safety in the long term. To control the damage caused by Sclerotinia diseases, as well as consider the fungicide resistance and chemical residues, strategy of which plant nutritional regulation, as an eco-friendly approach, is gaining much significance. Selenium (Se), as a beneficial microelement for plant, has been manifested to be effective in inhibiting the mycelial growth of S.sclerotiorum in our previous study. In the present study, we observed that Se (both selenate and selenite) inhibited the formation of sclerotia, which is an important life form in the disease cycle of S. sclerotiorum. And the inhibition ratios of number of sclerotia in treatments of Se(VI)5.0 and Se(IV)5.0 were 54.55% and 43.84%, respectively; the inhibition ratios of weight of sclerotia in treatments of Se(VI)5.0 and Se(IV)5.0 were 42.29% and 25.67%, respectively. Results suggested that Se inhibited mycelial growth, severely damaged sclerotial ultrastructure, reduced the capacity of acid production, decreased superoxide dismutase (SOD) and catalase (CAT) activities, increased the content of hydrogen peroxide (H2O2) and superoxide anion (O2-) in mycelium, and all of these resulted in the reduction in sclerotial formation. Further studies revealed that Se application in medium increased Se concentration in sclerotia and thus inhibited sclerotial germination. Moreover, the pathogenicity of mycelia germinating from sclerotia that pretreated with Se, decreased significantly to rape leaves. These findings broadened our understanding of Se application in plant protection, as well as provided evidences for developing environment-friendly fungicide for S. sclerotiorum control.


Assuntos
Ascomicetos/efeitos dos fármacos , Ascomicetos/patogenicidade , Fungicidas Industriais/farmacologia , Selênio/farmacologia , Antioxidantes/metabolismo , Ascomicetos/crescimento & desenvolvimento , Ascomicetos/metabolismo , Peróxido de Hidrogênio/metabolismo , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Micélio/metabolismo , Micélio/patogenicidade , Selênio/metabolismo , Virulência
16.
J Agric Food Chem ; 67(32): 8875-8883, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31347830

RESUMO

Glucan synthase (GLS) gene is known to be involved in the fungal biosynthesis of cell wall, differentiation, and growth. In the present study, a glucan synthase gene (GFGLS) in the edible mushroom Grifola frondosa with a full sequence of 5927 bp encoding a total of 1781 amino acids was cloned and characterized for the first time. GFGLSp is a membrane protein containing two large transmembrane domains connected with a hydrophilic cytoplasmic domain. With a constructed dual promoter RNA silencing vector pAN7-gfgls-dual, a GFGLS-silencing transformant iGFGLS-3 had the lowest GFGLS transcriptional expression level (26.1%) with a shorter length and thinner appearance of the mycelia, as well as decreased mycelial biomass and exo-polysaccharide production of 5.02 and 0.38 g/L, respectively. Further analysis indicated that GFGLS silence influenced slightly the monosaccharide compositions and ratios of mycelial and exo-polysaccharide. These findings suggest that GFGLS could affect mycelial growth and polysaccharide production by downregulating the glucan synthesis.


Assuntos
Polissacarídeos Fúngicos/biossíntese , Proteínas Fúngicas/metabolismo , Glucosiltransferases/metabolismo , Grifola/enzimologia , Micélio/crescimento & desenvolvimento , Proteínas Fúngicas/genética , Glucosiltransferases/genética , Grifola/genética , Grifola/crescimento & desenvolvimento , Grifola/metabolismo , Micélio/enzimologia , Micélio/genética , Micélio/metabolismo , Interferência de RNA , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo
17.
J Agric Food Chem ; 67(31): 8476-8484, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31298527

RESUMO

Cicada flowers, which are edible and medicinal mushrooms, are the fruiting bodies of Isaria cicadae, a fungus that is parasitic on the larvae of cicada pupae. We hypothesize that host factors might possess stimulatory activity on metabolite synthesis in Isaria cicadae. Here, we first compared the microbial community structures of different wild cicada flowers across geographical regions, compartments, and growth stages via high-throughput sequencing. Isaria cicadae TZC-3, an isolate of the most abundant operational taxonomic unit (OTU6782) in all the fungal communities, was isolated from wild cicada flowers. Furthermore, the effects of cicada pupae on metabolite synthesis in Isaria cicadae TZC-3 were studied in submerged culture. The contents of intercellular polysaccharides, adenosine, N6-(2-hydroxyethyl)-adenosine, free amino acids, and hydrolyzed monosaccharides in the mycelia cultured with cicada pupa powder (4%) were significantly increased as compared with the contents in the control group. This indicates that a cicada pupa can act as an elicitor for metabolite synthesis in Isaria cicadae.


Assuntos
Cordyceps/metabolismo , Carpóforos/química , Hemípteros/microbiologia , Pupa/microbiologia , Adenosina/análise , Adenosina/metabolismo , Aminoácidos/análise , Aminoácidos/metabolismo , Animais , Cordyceps/química , Cordyceps/crescimento & desenvolvimento , Carpóforos/crescimento & desenvolvimento , Carpóforos/metabolismo , Hemípteros/química , Hemípteros/metabolismo , Interações Hospedeiro-Patógeno , Microbiota , Micélio/química , Micélio/crescimento & desenvolvimento , Micélio/metabolismo , Pupa/química , Pupa/metabolismo
18.
J Microbiol Biotechnol ; 29(8): 1204-1211, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31336432

RESUMO

Fungal exopolysaccharides are important natural products having diverse biological functions. In this study, exopolysaccharides from Fomitopsis castanea mycelia (FEPS) were prepared, and the highest mushroom tyrosinase inhibitory activity was found. FEPS were prepared from cultivation broth by ethanol precipitation method. The extraction yield and protein concentration of FEPS were 213.1 mg/l and 0.03%, respectively. FEPS inhibited mushroom tyrosinase with the half maximal inhibitory concentration (IC50) of 16.5 mg/ml and dose-dependently inhibited cellular tyrosinase activity (63.9% at 50 µg/ml, and 83.3% at 100 µg/ml) in the cell-free extract of SK-MEL-5 human melanoma cell and α-melanocytestimulating hormone (α-MSH)-stimulated melanin formation in intact SK-MEL-5 human melanoma cell. The IC50 of FEPS against NO production from RAW264.7 macrophage cells was 42.8 ± 0.64 µg/ml. By in vivo study using a zebrafish model, exposure of FEPS at 400 µg/ml to dechorionated zebrafish embryos for 18 h decreased the pigment density, compared to that without FEPS-treated control.


Assuntos
Coriolaceae/metabolismo , Polissacarídeos Fúngicos/antagonistas & inibidores , Polissacarídeos Fúngicos/metabolismo , Melanoma/tratamento farmacológico , Micélio/metabolismo , Agaricales/enzimologia , Animais , Linhagem Celular Tumoral/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Polissacarídeos Fúngicos/isolamento & purificação , Humanos , Concentração Inibidora 50 , Melaninas/metabolismo , Melanócitos/efeitos dos fármacos , Melanoma Experimental , Camundongos , Monofenol Mono-Oxigenase/efeitos dos fármacos , Células RAW 264.7 , Peixe-Zebra , alfa-MSH/efeitos dos fármacos
19.
Environ Microbiol ; 21(10): 3909-3926, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31314937

RESUMO

The black morel (Morchella importuna Kuo, O'Donnell and Volk) was once an uncultivable wild mushroom, until the development of exogenous nutrient bag (ENB), making its agricultural production quite feasible and stable. To date, how the nutritional acquisition of the morel mycelium is fulfilled to trigger its fruiting remains unknown. To investigate the mechanisms involved in ENB decomposition, the genome of a cultivable morel strain (M. importuna SCYDJ1-A1) was sequenced and the genes coding for the decay apparatus were identified. Expression of the encoded carbohydrate-active enzymes (CAZymes) was then analyzed by metatranscriptomics and metaproteomics in combination with biochemical assays. The results show that a diverse set of hydrolytic and redox CAZymes secreted by the morel mycelium is the main force driving the substrate decomposition. Plant polysaccharides such as starch and cellulose present in ENB substrate (wheat grains plus rice husks) were rapidly degraded, whereas triglycerides were accumulated initially and consumed later. ENB decomposition led to a rapid increase in the organic carbon content in the surface soil of the mushroom bed, which was thereafter consumed during morel fruiting. In contrast to the high carbon consumption, no significant acquisition of nitrogen was observed. Our findings contribute to an increasingly detailed portrait of molecular features triggering morel fruiting.


Assuntos
Ascomicetos/genética , Ascomicetos/metabolismo , Carbono/metabolismo , Micélio/metabolismo , Proteoma/genética , Agricultura , Sequência de Bases , Nutrientes , Polissacarídeos/metabolismo
20.
Elife ; 82019 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-31307571

RESUMO

Mutualistic interactions between free-living algae and fungi are widespread in nature and are hypothesized to have facilitated the evolution of land plants and lichens. In all known algal-fungal mutualisms, including lichens, algal cells remain external to fungal cells. Here, we report on an algal-fungal interaction in which Nannochloropsis oceanica algal cells become internalized within the hyphae of the fungus Mortierella elongata. This apparent symbiosis begins with close physical contact and nutrient exchange, including carbon and nitrogen transfer between fungal and algal cells as demonstrated by isotope tracer experiments. This mutualism appears to be stable, as both partners remain physiologically active over months of co-cultivation, leading to the eventual internalization of photosynthetic algal cells, which persist to function, grow and divide within fungal hyphae. Nannochloropsis and Mortierella are biotechnologically important species for lipids and biofuel production, with available genomes and molecular tool kits. Based on the current observations, they provide unique opportunities for studying fungal-algal mutualisms including mechanisms leading to endosymbiosis.


Assuntos
Endocitose , Mortierella/metabolismo , Micélio/metabolismo , Fotossíntese , Estramenópilas/metabolismo , Simbiose , Biocombustíveis , Metabolismo dos Lipídeos , Mortierella/crescimento & desenvolvimento , Micélio/crescimento & desenvolvimento , Estramenópilas/crescimento & desenvolvimento
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