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1.
PLoS One ; 18(8): e0290167, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37582116

RESUMO

In practical production, cane stems with buds are generally used as seed for propagation. However, long-terms cane stems only easily lead to some problems such as disease sensitivity, quality loss, etc. Recently, cane seedings, which are produced by tissue culture were used in sugarcane production, but few studies on cane health related to tissue culture seedings. Therefore, to evaluate the immunity and health of sugarcanes growing from different reproduction modes, the endophytic microbial compositions in cane roots between stem and tissue culture seedlings were analyzed using high-throughput techniques. The results showed that the endophytic microbial compositions in cane roots were significant differences between stem and tissue culture seedlings. At the genus level, Pantoea, Bacillus, Streptomyces, Lechevalieria, Pseudomonas, Nocardioides, unclassified_f__Comamonadaceae enriched as the dominant endophytic bacterial genera, and Rhizoctonia, Sarocladium, Scytalidium, Wongia, Fusarium, unclassified_f__Phaeosphaer, unclassified_c__Sordariom, unclassified_f__Stachybot, Poaceascoma, Microdochium, Arnium, Echria, Mycena and Exophiala enriched as the dominant endophytic fungal genera in cane roots growing from the tissue culture seedlings. In contrast, Mycobacterium, Massilia, Ralstonia, unclassified_f__Pseudonocardiacea, norank_f__Micropepsaceae, Leptothrix and Bryobacter were the dominant endophytic bacterial genera, and unclassified_k__Fungi, unclassified_f__Marasmiaceae, Talaromyces, unclassified_c__Sordariomycetes and Trichocladium were the dominant endophytic fungal genera in cane roots growing from stem seedlings. Additionally, the numbers of bacterial and fungal operational taxonomic units (OTUs) in cane roots growing from tissue culture seedlings were significantly higher than those of stem seedlings. It indicates that not only the endophytic microbial compositions in cane roots can be shaped by different propagation methods, but also the stress resistance of sugarcanes can be improved by the tissue culture propagation method.


Assuntos
Actinomycetales , Agaricales , Ascomicetos , Fungos não Classificados , Fusarium , Sordariales , Streptomyces , Bengala , Raízes de Plantas/microbiologia , Endófitos
2.
PeerJ ; 11: e15454, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37547726

RESUMO

In natural and agricultural systems, the plant microbiome-the microbial organisms associated with plant tissues and rhizosphere soils-has been shown to have important effects on host physiology and ecology, yet we know little about how these plant-microbe relationships play out in urban environments. Here we characterize the composition of fungal communities associated with living leaves of one of the most common sidewalk trees in the city of San Francisco, California. We focus our efforts on endophytic fungi (asymptomatic microfungi that live inside healthy leaves), which have been shown in other systems to have large ecological effects on the health of their plant hosts. Specifically, we characterized the foliar fungal microbiome of Metrosideros excelsa (Myrtaceae) trees growing in a variety of urban environmental conditions. We used high-throughput culturing, PCR, and Sanger sequencing of the internal transcribed spacer nuclear ribosomal DNA (ITS nrDNA) region to quantify the composition and structure of fungal communities growing within healthy leaves of 30 M. excelsa trees from six distinct sites, which were selected to capture the range of environmental conditions found within city limits. Sequencing resulted in 854 high-quality ITS sequences. These sequences clustered into 85 Operational Taxonomic Units (97% OTUs). We found that these communities encompass relatively high alpha (within) and beta (between-site) diversity. Because the communities are all from the same host tree species, and located in relatively close geographical proximity to one another, these analyses suggest that urban environmental factors such as heat islands or differences in vegetation or traffic density (and associated air quality) may potentially be influencing the composition of these fungal communities. These biogeographic patterns provide evidence that plant microbiomes in urban environments can be as dynamic and complex as their natural counterparts. As human populations continue to transition out of rural areas and into cities, understanding the factors that shape environmental microbial communities in urban ecosystems stands to become increasingly important.


Assuntos
Fungos não Classificados , Microbiota , Humanos , Endófitos/genética , Cidades , São Francisco , Temperatura Alta , Plantas/microbiologia , Árvores/microbiologia
3.
PLoS One ; 18(7): e0287990, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37471328

RESUMO

Eukaryotic hosts harbor tremendously diverse microbiomes that affect host fitness and response to environmental challenges. Fungal endophytes are prominent members of plant microbiomes, but we lack information on the diversity in functional traits affecting their interactions with their host and environment. We used two culturing approaches to isolate fungal endophytes associated with the widespread, dominant prairie grass Andropogon gerardii and characterized their taxonomic diversity using rDNA barcode sequencing. A randomly chosen subset of fungi representing the diversity of each leaf was then evaluated for their use of different carbon compound resources and growth on those resources. Applying community phylogenetic analyses, we discovered that these fungal endophyte communities are comprised of phylogenetically distinct assemblages of slow- and fast-growing fungi that differ in their use and growth on differing carbon substrates. Our results demonstrate previously undescribed and cryptic functional diversity in carbon resource use and growth in fungal endophyte communities of A. gerardii.


Assuntos
Fungos não Classificados , Micobioma , Micobioma/genética , Poaceae , Filogenia , Fungos , Endófitos/fisiologia
4.
Microbiol Res ; 263: 127128, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35868260

RESUMO

The olive crop has expanded in the southeastern region of South America, particularly in Brazil. Thus, the objectives of this study were to identify the diversity of endophytic microorganisms associated with olive leaves with culture-dependent and culture-independent methods, to explore which factors influence the composition and abundance of this microbial community, to identify the trophic mode of these fungi by FunGuild and, to verify type associations between bacterial and fungal communities. Leaf samples were collected from 93 plants in nine locations in the Brazilian states of São Paulo and Minas Gerais. Leaves were first superficially disinfected before fungal isolation and next-generation metabarcoding sequencing was completed targeting the 16S rRNA regions for bacteria and ITS1 for fungi. In total, 800 isolates were obtained, which were grouped into 191 morphotypes and molecularly identified, resulting in 38 genera, 32 of which were recorded for the first time in cultivated olive trees in Brazil. For the isolated fungi, the most abundant trophic level was pathotrophic and for the culture-independent method was unidentified followed by symbiotrophic. The metabarcoding results revealed that factors such as plant age, altitudinal gradient, and geographic location can influence the microbial community of commercial olive plants, while the specific cultivar did not.


Assuntos
Fungos não Classificados , Olea , Bactérias , Brasil , Endófitos , Fungos , Olea/microbiologia , Folhas de Planta/microbiologia , RNA Ribossômico 16S/genética
5.
Microbiol Res ; 261: 127058, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35576789

RESUMO

The bacterial wilt caused by Ralstonia solanacearum is a destructive plant disease globally. Since a completely non-biological control measure could be a matter of environmental concern, investigations of developing eco-friendly strategies are required to control this phytopathogen. Attenuation of the bacterial virulence in addition to destroying the pathogen may be an alternative and overarching approach to control this disease. In this study, we have explored the potentiality of a vertically transmitted endophytic fungus Penicillium sp. PM031 isolated from stem of in vitro grown, wilt susceptible tomato cultivar to control this phytopathogen. The endophytic fungus was unable to inhibit the bacterial growth during direct confrontation in co-culture system; rather its growth and extracellular secretion were affected by the bacterium. Interestingly, the PM031-derived endo-metabolites, containing ~80% of lipid molecules, showed the dose-dependent growth inhibitory effect against R. solanacearum. Metabolite treatment with a concentration of 2500 and 5000 µg/ml significantly inhibited the bacterial growth 24.72% and 64.31%, respectively. Higher concentrations of endo-metabolite treatment exhibited antibacterial activity by rupturing cellular membranes. Furthermore, the endo-metabolites negatively influence the virulence factors necessary in early phases of bacterial infection, such as motility and biofilm formation. Our study highlights even if an endophytic fungus associated with the susceptible host plant cannot tackle R. solanacearum directly, its lipid-rich metabolites have potential to attenuate the virulence of phytopathogen. We believe this study can be a stepping stone to develop suitable formulations to control the bacterial wilt in a sustainable way, which will reduce excessive uses of synthetic bactericides.


Assuntos
Fungos não Classificados , Penicillium , Ralstonia solanacearum , Solanum lycopersicum , Antibacterianos/farmacologia , Bactérias/metabolismo , Endófitos/metabolismo , Lipídeos , Solanum lycopersicum/microbiologia , Penicillium/metabolismo , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Fatores de Virulência/metabolismo
6.
mSystems ; 7(2): e0009122, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35293790

RESUMO

Symbiosis with bacteria is widespread among eukaryotes, including fungi. Bacteria that live within fungal mycelia (endohyphal bacteria) occur in many plant-associated fungi, including diverse Mucoromycota and Dikarya. Pestalotiopsis sp. strain 9143 is a filamentous ascomycete isolated originally as a foliar endophyte of Platycladus orientalis (Cupressaceae). It is infected naturally with the endohyphal bacterium Luteibacter sp. strain 9143, which influences auxin and enzyme production by its fungal host. Previous studies have used transcriptomics to examine similar symbioses between endohyphal bacteria and root-associated fungi such as arbuscular mycorrhizal fungi and plant pathogens. However, currently there are no gene expression studies of endohyphal bacteria of Ascomycota, the most species-rich fungal phylum. To begin to understand such symbioses, we developed methods for assessing gene expression by Pestalotiopsis sp. and Luteibacter sp. when grown in coculture and when each was grown axenically. Our assays showed that the density of Luteibacter sp. in coculture was greater than in axenic culture, but the opposite was true for Pestalotiopsis sp. Dual-transcriptome sequencing (RNA-seq) data demonstrate that growing in coculture modulates developmental and metabolic processes in both the fungus and bacterium, potentially through changes in the balance of organic sulfur via methionine acquisition. Our analyses also suggest an unexpected, potential role of the bacterial type VI secretion system in symbiosis establishment, expanding current understanding of the scope and dynamics of fungal-bacterial symbioses. IMPORTANCE Interactions between microbes and their hosts have important outcomes for host and environmental health. Foliar fungal endophytes that infect healthy plants can harbor facultative endosymbionts called endohyphal bacteria, which can influence the outcome of plant-fungus interactions. These bacterial-fungal interactions can be influential but are poorly understood, particularly from a transcriptome perspective. Here, we report on a comparative, dual-RNA-seq study examining the gene expression patterns of a foliar fungal endophyte and a facultative endohyphal bacterium when cultured together versus separately. Our findings support a role for the fungus in providing organic sulfur to the bacterium, potentially through methionine acquisition, and the potential involvement of a bacterial type VI secretion system in symbiosis establishment. This work adds to the growing body of literature characterizing endohyphal bacterial-fungal interactions, with a focus on a model facultative bacterial-fungal symbiosis in two species-rich lineages, the Ascomycota and Proteobacteria.


Assuntos
Ascomicetos , Fungos não Classificados , Gammaproteobacteria , Sistemas de Secreção Tipo VI , Xanthomonadaceae , Simbiose , Endófitos , Pestalotiopsis , Ascomicetos/genética , Bactérias/genética , Plantas , Metionina
7.
PLoS One ; 17(3): e0264673, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35298472

RESUMO

Oroxylum indicum (L.) Kurz, a medicinal plant, shows numerous pharmacological properties which may be attributed to the bioactive compounds produced by O. indicum or due to associated endophytes. In the present study, leaf of O. indicum was evaluated for the presence of associated fungal endophytes, and antioxidant and cytotoxic activities of bioactive compounds produced from them. Using culture-dependent approach, eight fungal endophytes belonging to five different genera were identified. Two endophytes Daldinia eschscholtzii and Ectophoma multirostrata have been reported for the first time from the leaf of O. indicum plant. High-performance thin-layer chromatography (HPTLC) of ethyl acetate (EA) extract of isolated fungal endophytes showed a distinct fingerprinting profile in EA extract of Colletotrichum gloeosporioides. Among identified endophytes, EA extract of C. gloeosporioides showed significant antioxidant activity against DPPH free radical, superoxide anion radical, nitric oxide radical and hydroxyl radical with EC50 values of 22.24±1.302 µg/mL, 67.46±0.576 µg/mL, 80.10±0.706 µg/mL and 61.55±1.360 µg/mL, respectively. EA extract of C. gloeosporioides exhibited potential cytotoxicity against HCT116, HeLa and HepG2 cancer cell lines with IC50 values of 76.59 µg/mL, 176.20 µg/mL and 1750.70 µg/mL, respectively. A comparative HPTLC fingerprinting and the antioxidant activity of C. gloeosporioides associated with two different hosts (leaf of O. indicum and dead twigs of other plant) showed that C. gloeosporioides produces bioactive compounds in a host-dependent manner.


Assuntos
Bignoniaceae , Fungos não Classificados , Antioxidantes/metabolismo , Bioprospecção , Endófitos/metabolismo , Extratos Vegetais/química
8.
BMC Ecol Evol ; 22(1): 18, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-35168544

RESUMO

BACKGROUND: While a considerable amount of research has explored plant community composition in primary successional systems, little is known about the microbial communities inhabiting these pioneer plant species. Fungal endophytes are ubiquitous within plants, and may play major roles in early successional ecosystems. Specifically, endophytes have been shown to affect successional processes, as well as alter host stress tolerance and litter decomposition dynamics-both of which are important components in harsh environments where soil organic matter is still scarce. RESULTS: To determine possible contributions of fungal endophytes to plant colonization patterns, we surveyed six of the most common woody species on the Pumice Plain of Mount St. Helens (WA, USA; Lawetlat'la in the Cowlitz language; created during the 1980 eruption)-a model primary successional ecosystem-and found low colonization rates (< 15%), low species richness, and low diversity. Furthermore, while endophyte community composition did differ among woody species, we found only marginal evidence of temporal changes in community composition over a single field season (July-September). CONCLUSIONS: Our results indicate that even after a post-eruption period of 40 years, foliar endophyte communities still seem to be in the early stages of community development, and that the dominant pioneer riparian species Sitka alder (Alnus viridis ssp. sinuata) and Sitka willow (Salix sitchensis) may be serving as important microbial reservoirs for incoming plant colonizers.


Assuntos
Fungos não Classificados , Micobioma , Salix , Ecossistema , Endófitos , Plantas , Microbiologia do Solo
9.
Biotechnol Genet Eng Rev ; 37(2): 154-177, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34666635

RESUMO

The endosphere represents intracellular regions within plant tissues colonize by microbial endophytes without causing disease symptoms to host plants. Plants harbor one or two endophytic microbes capable of synthesizing metabolite compounds. Environmental factors determine the plant growth and survival as well as the kind of microorganisms associated with them. Some fungal endophytes that symbiotically colonize the endosphere of medicinal plants with the potential of producing biological products have been employed in traditional and modern medicine. The bioactive resources from endophytic fungi are promising; biotechnologically to produce cheap and affordable commercial bioactive products as alternatives to chemical drugs and other compounds. The exploration of bioactive metabolites from fungal endophytes has been found applicable in agriculture, pharmaceutical, and industries. Thus, fungal endophytes can be engineered to produce a substantive quantity of pharmacological drugs through the biotransformation process. Hence, this review shall provide an overview of fungal endophytes, ecology, their bioactive compounds, and exploration with the biosystematics approach.


Assuntos
Produtos Biológicos , Fungos não Classificados , Plantas Medicinais , Endófitos , Fungos
10.
Plant Physiol Biochem ; 168: 465-476, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34717178

RESUMO

Expansins are proteins involved in cell wall metabolism that play an important role in plant growth, development, fruit ripening and abiotic stress tolerance. In the present study, we analyzed putative expansins that respond to drought stress. Five expansin genes were identified in cDNA libraries isolated from Colobanthus quitensis gown either with or without endophytic fungi under hydric stress. A differential transcript abundance was observed by qPCR analysis upon drought stress. To compare these expansin genes, and to suggest a possible mechanism of action at the molecular level, the structural model of the deduced proteins was obtained by comparative modeling methodology. The structures showed two domains and an open groove on the surface of the proteins was observed in the five structural models. The proteins were evaluated in terms of their protein-ligand interactions using four different ligands. The results suggested differences in their mode of protein-ligand interaction, in particular concerning the residues involved in the protein-ligand interaction. The presented evidence supports the participation of some members of the expansin multiprotein family in the response to drought stress in C. quitensis and suggest that the response is modulated by endophytic fungi.


Assuntos
Caryophyllaceae , Fungos não Classificados , Regiões Antárticas , Secas , Endófitos , Proteínas de Plantas/genética
11.
PLoS One ; 16(5): e0250954, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33983974

RESUMO

Marine fungi and, particularly, endophytic species have been recognised as one of the most prolific sources of structurally new and diverse bioactive secondary metabolites with multiple biotechnological applications. Despite the increasing number of bioprospecting studies, very few have already evaluated the cosmeceutical potential of marine fungal compounds. Thus, this study focused on a frequent seaweed in the Portuguese coast, Halopteris scoparia, to identify the endophytic marine fungi associated with this host, and assess their ability to biosynthesise secondary metabolites with antioxidative, enzymatic inhibitory (hyaluronidase, collagenase, elastase and tyrosinase), anti-inflammatory, photoprotective, and antimicrobial (Cutibacterium acnes, Staphylococcus epidermidis and Malassezia furfur) activities. The results revealed eight fungal taxa included in the Ascomycota, and in the most representative taxonomic classes in marine ecosystems (Eurotiomycetes, Sordariomycetes and Dothideomycetes). These fungi were reported for the first time in Portugal and in association with H. scoparia, as far as it is known. The screening analyses showed that most of these endophytic fungi were producers of compounds with relevant biological activities, though those biosynthesised by Penicillium sect. Exilicaulis and Aspergillus chevalieri proved to be the most promising ones for being further exploited by dermocosmetic industry. The chemical analysis of the crude extract from an isolate of A. chevalieri revealed the presence of two bioactive compounds, echinulin and neoechinulin A, which might explain the high antioxidant and UV photoprotective capacities exhibited by the extract. These noteworthy results emphasised the importance of screening the secondary metabolites produced by these marine endophytic fungal strains for other potential bioactivities, and the relevance of investing more efforts in understanding the ecology of halo/osmotolerant fungi.


Assuntos
Ascomicetos/metabolismo , Endófitos/metabolismo , /microbiologia , Antibacterianos/farmacologia , Antifúngicos/farmacologia , Ascomicetos/enzimologia , Ascomicetos/isolamento & purificação , Bioprospecção/métodos , Ecossistema , Endófitos/enzimologia , Fungos/isolamento & purificação , Fungos/metabolismo , Fungos não Classificados/isolamento & purificação , Fungos não Classificados/metabolismo , Testes de Sensibilidade Microbiana , Portugal , Alga Marinha/microbiologia
12.
Microbiol Res ; 231: 126353, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31707299

RESUMO

Cladosporium spp. is a cosmopolitan fungal genus. In the literature, it has been reported as a biological agent for controlling several plant diseases, but its mechanism of action has never been clarified. The present study aims to identify Cladosporium spp. based on the DNA phylogeny of nine isolates obtained from the phylloplane of rice and their potential antagonistic activity against the main fungal pathogens that affect rice crop. Nine isolates of Cladosporium spp. were identified based on DNA phylogeny, molecular and morphological characterization, and their antagonistic effects with the rice pathogens C. miyabeanus, M. oryzae, M. albescens and S. oryzae. Four isolates were selected to study lytic enzymes such as ß-1,3-glucanase, chitinase and protease, and only one isolate was selected for a conidial germination and appressoria formation assay. The nine isolates were identified as C. cladosporioides, C. tenuissimum and C. subuliforme. Four isolates, identified as C. cladosporioides, inhibited the mycelial growth of rice pathogens such as C1H (68.59%) of S. oryzae, C5 G (74.32%) of C. miyabeanus, C11 G (75.97%) of M. oryzae and C24 G (77.39%) of M. albescens. C24 G showed a high activity of lytic enzymes, was tested against C. miyabeanus and M. oryzae, and inhibited conidial germination and appressorium formation by more than 59.36%. The characterization of C. cladosporioides suggested this species as a potential bioagent for the management of several rice diseases, especially rice blast. This is the first time that a potential biological agent from the genus Cladosporium identified at the species level was isolated from the rice phylloplane, and some of its mechanisms of action were demonstrated, such as increasing lytic enzyme activity against rice pathogens.


Assuntos
Cladosporium , Folhas de Planta/microbiologia , Patologia Vegetal , Antibiose , Ascomicetos/crescimento & desenvolvimento , Agentes de Controle Biológico , Quitinases/metabolismo , Cladosporium/enzimologia , Cladosporium/genética , Cladosporium/isolamento & purificação , DNA Ribossômico , Fungos não Classificados/crescimento & desenvolvimento , Glicosídeo Hidrolases/metabolismo , Magnaporthe/crescimento & desenvolvimento , Micoses , Oryza/microbiologia , Peptídeo Hidrolases/metabolismo , Filogenia , Doenças das Plantas
13.
Food Chem ; 310: 125927, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31835232

RESUMO

Two filamentous fungi (Actinomucor elegans and Umbelopsis isabellina), were tested for their ability to enrich white grape pomace simultaneously with both γ-linolenic acid (GLA) and carotenoids through solid-state fermentation (SSF) processes. U. isabellina presented higher ability to produce GLA-rich lipids (composed mainly of neutral fractions) than A. elegans (the 6-th day of SSF: 378.85 mg/100 g of pomace -U. isabellina and 193.36 mg/100 g of pomace- A. elegans). The amounts of ß-carotene and lutein for both SSFs gradually increased until the end of the fermentation processes. The effect of fermentation time on the phenolic content and antioxidant activity of grape pomace was also studied. The SSF with A. elegans increased significantly total phenolic and flavonoid contents and DPPH scavenging activity of grape popmace. These bioprocessed grape pomaces with significant amounts of carotenoids and GLA-rich lipids (>94% nutritionally-valuable polyunsaturated fatty acids at the sn-2 position) could be very attractive for food industry.


Assuntos
Antioxidantes/química , Carotenoides/química , Manipulação de Alimentos/métodos , Fungos não Classificados/metabolismo , Vitis/química , Ácido gama-Linolênico/química , Antioxidantes/metabolismo , Carotenoides/metabolismo , Fermentação , Flavonoides/metabolismo , Lipídeos/análise , Lipídeos/química , Fenóis/análise , Fenóis/metabolismo , beta Caroteno/metabolismo , Ácido gama-Linolênico/metabolismo
14.
PLoS One ; 14(5): e0217060, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31112560

RESUMO

In the present study, endophytic fungi have been isolated from various parts of the medicinal herb Hypericum perforatum (St. John's Wort), which is known as a source of medically important metabolites. The isolated strains were cultured in liquid media and their ability to synthesize hypericin, the secondary metabolite of the host and its suspected precursor, emodin was tested analyzing the extracts of the fermentation broth and the mycelia. The HPLC-UV analysis of the chloroform/methanol extracts of the mycelia revealed that three isolates were able to produce emodin (SZMC 23771, 19.9 ng/mg; SZMC 23772, 20.8 ng/mg; SZMC 23769, 427.9 ng/mg) and one of them also could synthesize hypericin (SZMC 23769, 320.4 ng/mg). These results were also confirmed via UHPLC-HRMS technique both in full scan and MS/MS mode. The strains producing only emodin belong to the section Alternata of the genus Alternaria, while the isolate producing both metabolites was identified as Epicoccum nigrum. The mycelial extracts of E. nigrum and the Alternaria sp. SZMC 23772 showed higher inhibitory activities in the antimicrobial tests against the six selected bacteria compared to the hypericin and emodin standards in the applied concentration (100 µg/mL), while in case of the Alternaria sp. SZMC 23771 lower inhibition activities were observed on Staphylococcus aureus and Streptomyces albus than the pure compounds.


Assuntos
Anti-Infecciosos/química , Fungos não Classificados/metabolismo , Hypericum/química , Hypericum/microbiologia , Extratos Vegetais/química , Antracenos , Clorofórmio , Cromatografia Líquida de Alta Pressão , Emodina/química , Fermentação , Microbiologia Industrial , Metanol , Testes de Sensibilidade Microbiana , Perileno/análogos & derivados , Perileno/química , Filogenia , Plantas Medicinais/química , Plantas Medicinais/microbiologia , Metabolismo Secundário , Staphylococcus aureus/efeitos dos fármacos , Streptomyces/efeitos dos fármacos , Espectrometria de Massas em Tandem
15.
Bioresour Technol ; 278: 138-144, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30685617

RESUMO

An acidic cultivation strategy was developed to prevent contamination of a lethal fungus Paraphysoderma sedebokerensis in Haematococcus pluvialis culture for astaxanthin production. Instead of generally used neutral pH, an acidic condition (pH 4) was applied to the cultivation, resulting in a significant inhibition of the fungal contamination. This could be ascribed to the acidity-associated denaturation of a surface protein of P. sedebokerensis, which plays an important role in recognition of H. pluvialis. Stress relief strategies including stepwise light irradiation and naturally occurring nitrogen deficiency were employed in the induction stage to minimize the reduction of astaxanthin production caused by acidic pH. Accordingly, an astaxanthin titer of 84.8 mg L-1 was obtained, which is 141-fold of that from the completely contaminated culture and double of that without the stress relief methods. This strategy provides a persistent contamination control method that can be used for practical astaxanthin production by H. pluvialis.


Assuntos
Clorofíceas/metabolismo , Fungos não Classificados/metabolismo , Ácidos , Concentração de Íons de Hidrogênio , Nitrogênio/metabolismo , Xantofilas/biossíntese
16.
PLoS One ; 13(6): e0197359, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29897911

RESUMO

Mangrove endophytic fungi can produce impressive quantities of metabolites with promising antioxidant activities that may be useful to humans as novel physiological agents. In this study, we investigated the phylogenetic diversity and antioxidant potential of 46 fungal endophytes derived from the mangrove species Rhizophora stylosa and R. mucronata from the South China Sea. The fungal isolates were identified using a combination of morphological characteristics and phylogenetic analysis of the internal transcribed spacer (ITS) sequences. Seventeen genera belonging to 8 taxonomic orders of Ascomycota were discovered, specifically, Botryosphaeriales, Capnodiales, Diaporthales, Eurotiales, Glomerellales, Hypocreales, Pleosporales, and Xylariales. The most abundant fungal orders included Xylariales (35.49%) and Diaporthales (27.61%), which were predominantly represented by the culturable species Pestalotiopsis sp. (34.54%) and Diaporthe sp. (18.62%). The stems showed more frequent colonization and species diversity than the roots, leaves, hypocotyls, and flower tissues of the host plant. The antioxidant activities of all the isolated fungal extracts on four different culture media were assessed using improved 2,2'-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonicacid) (ABTS) methods. A relatively high proportion (84.8%) of the isolates displayed antioxidant capacity (%RSA > 50%). Further research also provided the first evidence that HQD-6 could produce flufuran as a significant radical scavenger with IC50 values of 34.85±1.56 and 9.75±0.58 µg/mL, respectively. Our findings suggest that the utilization of a biotope such as that of the endophytic fungal community thriving on the mangrove plants R. stylosa and R. mucronata may be suitable for use as a sustainable resource for natural antioxidants.


Assuntos
Variação Genética , Filogenia , Rhizophoraceae/genética , Antioxidantes/química , Antioxidantes/farmacologia , DNA Espaçador Ribossômico , Endófitos/química , Endófitos/genética , Fungos não Classificados/química , Fungos não Classificados/genética , Humanos , Rhizophoraceae/química , Áreas Alagadas
17.
PLoS One ; 13(6): e0199677, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29933393

RESUMO

The study reports the response to herbicide of the 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading fungal strain Umbelopsis isabellina. A comparative analysis covered 41 free amino acids as well as 140 lipid species of fatty acids, phospholipids, acylglycerols, sphingolipids, and sterols. 2,4-D presence led to a decrease in fungal catalase activity, associated with a higher amount of thiobarbituric acid-reactive substances (TBARS). Damage to cells treated with the herbicide resulted in increased membrane permeability and decreased membrane fluidity. Detailed lipidomic profiling showed changes in the fatty acids composition such as an increase in the level of linoleic acid (C18:2). Moreover, an increase in the phosphatidylethanolamine/phosphatidylcholine ratio was observed. Analysis of fungal lipid profiles revealed that the presence of 2,4-D was accompanied by the accumulation of triacylglycerols, a decrease in ergosterol content, and a considerable rise in the level of sphingolipid ceramides. In the exponential phase of growth, increased levels of leucine, glycine, serine, asparagine, and hydroxyproline were found. The results obtained in our study confirmed that in the cultures of U. isabellina oxidative stress was caused by 2,4-D. The herbicide itself forced changes not only to membrane lipids but also to neutral lipids and amino acids, as the difference of tested compounds profiles between 2,4-D-containing and control samples was consequently lower as the pesticide degradation progressed. The presented findings may have a significant impact on the basic understanding of 2,4-D biodegradation and may be applied for process optimization on metabolomic and lipidomic levels.


Assuntos
Ácido 2,4-Diclorofenoxiacético , Membrana Celular/metabolismo , Fungos não Classificados/metabolismo , Herbicidas , Lipídeos de Membrana/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ácido 2,4-Diclorofenoxiacético/metabolismo , Ácido 2,4-Diclorofenoxiacético/farmacologia , Herbicidas/metabolismo , Herbicidas/farmacologia
18.
Mycorrhiza ; 28(3): 213-219, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29335775

RESUMO

In 1977, the fine root endophyte, originally named Rhizophagus tenuis, was transferred into the genus Glomus as G. tenue, thus positioning the species with all other known arbuscular mycorrhizal fungi (Glomeromycota, Glomeromycotina). Recent molecular evidence, however, places it in a different subphylum, Mucoromycotina in the Mucoromycota. No suitable genus exists in the Mucoromycotina to accommodate G. tenue, so it is moved to Planticonsortium gen. nov. as P. tenue comb. nov.


Assuntos
Endófitos/classificação , Fungos não Classificados/classificação , Glomeromycota/classificação , Micorrizas/classificação , Endófitos/citologia , Fungos não Classificados/citologia , Glomeromycota/citologia , Micorrizas/citologia , Raízes de Plantas/microbiologia
19.
Z Naturforsch C J Biosci ; 73(1-2): 59-66, 2018 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-29161234

RESUMO

(9Z)-Methyl 4-dihydrotrisporate B and (9Z)-methyl trisporate B, pheromones of Zygomycetes fungi, have been synthesized using Stille cross-coupling from previously described cyclohexenone precursors. Conducting the coupling without protection groups allowed for a short and stereospecific synthesis route of the late trisporoids. Stability studies for both the compounds revealed (9Z)-methyl trisporate B to be very unstable against UV irradiation.


Assuntos
Carotenoides/síntese química , Cicloexenos/síntese química , Ácidos Graxos Insaturados/síntese química , Fungos não Classificados/química , Fator de Acasalamento/síntese química , Terpenos/síntese química , Fungos não Classificados/metabolismo , Fator de Acasalamento/efeitos da radiação , Raios Ultravioleta
20.
PLoS One ; 12(7): e0179718, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28678844

RESUMO

In this study, a culture-independent Illumina MiSeq sequencing strategy was applied to investigate the microbial communities colonizing the ancient painted sculptures of the Maijishan Grottoes, a famous World Cultural Heritage site listed by UNESCO in China. Four mixed samples were collected from Cave 4-4 of the Maijishan Grottoes, the so-called Upper Seven Buddha Pavilion, which was built during the Northern Zhou Dynasty (557-581AD). The 16/18S rRNA gene-based sequences revealed a rich bacterial diversity and a relatively low fungal abundance, including the bacterial groups Actinobacteria, Acidobacteria, Bacteroidetes, Cyanobacteria, Chloroflexi, Firmicutes, Proteobacteria and Verrucomicrobia and the fungal groups Ascomycota, Basidiomycota and Chytridiomycota. Among them, the bacteria genera of Pseudonocardia and Rubrobacter and unclassified fungi in the order of Capnodiales were dominant. The relative abundance of Pseudonocardia in the painted layer samples was higher than that in the dust sample, while Cyanobacteria dominated in the dust sample. Many of them have been discovered at other cultural heritage sites and associated with the biodeterioration of cultural relics. The presence and activity of these pioneering microorganisms may lead to an unexpected deterioration of the painted sculptures that are preserved in this heritage site. Thus, proper management strategies and potential risk monitoring should be used in the Maijishan Grottoes to improve the conservation of these precious painted sculptures.


Assuntos
Cavernas/microbiologia , Microbiologia do Solo , China , Cianobactérias/genética , Fungos não Classificados/genética , Fungos não Classificados/isolamento & purificação , Consórcios Microbianos , Tipagem Molecular , Pinturas , RNA Ribossômico 16S/genética , Escultura
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