Primera evidencia de actividad enzimática nitrilasa en Xylaria sp., y su relación con la biosíntesis de ácido indol-3-acético / First evidence of nitrilase enzymatic activity of Xylaria sp. and its relationship with the biosynthesis of indole-3-acetic acid

Resumen Muchos de los hongos degradadores de madera están implicados en la síntesis de metabolitos bioactivos de naturaleza antimicrobiana y terapéutica, así como de compuestos de importancia biotecnológica, incluyendo derivados indólicos, entre otros. Estos hongos brindan ciertos beneficios ecológicos a las plantas, entre los que se destacan la protección contra fitopatógenos y la promoción del crecimiento radicular. Xylaria sp. es un hongo degradador de celulosa (lignocelulolítico) con potencial biotecnológico. El ácido indol-3-acético (AIA) desempeña un papel sumamente importante en las interacciones planta-microorganismo, ya que es esencial para la fisiología y el correcto desarrollo morfológico vegetal. Se sabe que las enzimas nitrilo-hidrolíticas (nitrilasas) están involucradas en la síntesis de compuestos indólicos en las plantas, no obstante, se dispone de poca información acerca de la naturaleza de estas enzimas en el reino de los hongos. A través de una aproximación bioquímica y de genética molecular, se demuestra por primera vez que Xylaria sp. posee actividad enzimática nitrilasa utilizando compuestos ricos en nitrógeno y carbono como sustrato. La cepa estudiada aumentó sus niveles de expresión génica relativa y mostró crecimiento micelial, ambos en presencia de compuestos químicos como cianobenceno y KCN. Los resultados de este trabajo sugieren que el microorganismo es capaz de degradar moléculas nitrogenadas complejas. Por otra parte, mediante biofertilización con extractos fúngicos, se observó que Xylaria sp. promueve el desarrollo del sistema radicular de plántulas de Arabidopsis thaliana, además de sintetizar AIA.

Abstract Endophytic fungi inhabit plant tissues internally and asymptomatically, and many of them are involved in the synthesis of bioactive metabolites of antifungal and therapeutic nature, as well as other compounds of biotechnological importance including indole derivatives, among many others. Ecologically, they provide some benefits to plants including protection against phy-topathogens and promotion of root growth. In this sense, Xylaria sp. is a cellulose-decomposing fungus with biotechnological potential. It is worth mentioning that indole-3-acetic acid (IAA) also plays an extremely important role in plant-micro-organism interactions, as it is essential for physiology and proper plant morphological development. It is known that nitrile-hydrolytic enzymes (nitrilases) are involved in the synthesis of plant indole compounds; however, relatively little information is available concerning the nature of these enzymes in the fungal kingdom. In view of the above, through a biochemical and molecular-genetic approach, it has been demon-strated for the first time that Xylaria sp. carries out nitrile-hydrolytic enzyme activity using nitrogen and carbonrich compounds as substrate. The studied strain increased its relative gene expression levels and showed mycelial growth, both in the presence of chemical compounds such as cyanobenzene and KCN. Thus, the results of this work suggest that the micro-organism is capable of degrading complex nitrogenous molecules. On the other hand, through fungal biofertilization, it was observed that Xylaria sp. promotes the development of the root system of Arabidopsis thaliana seedlings, in addition to synthesizing IAA.

Steroids and dihydroisocoumarin glycosides from Xylaria sp. by the one strain many compounds strategy and their bioactivities / 中国天然药物

The fungus Xylaria sp. KYJ-15 was isolated from Illigera celebica. Based on the one strain many compounds (OSMAC) strategy, the strain was fermented on potato and rice solid media, respectively. As a result, two novel steroids, xylarsteroids A (1) and B (2), which are the first examples of C28-steroid with an unusual β- and γ-lactone ring, respectively, along with two new dihydroisocoumarin glycosides, xylarglycosides A (3) and B (4), were identified. Their structures were elucidated by spectroscopic methods, X-ray diffraction and electronic circular dichroism (ECD) experiments. All isolated compounds were evaluated for cytotoxicity, DPPH radical scavenging activity, acetylcholinesterase inhibitory and antimicrobial effect. Compound 1 exhibited potent AChE inhibitory activity with an IC50 value of 2.61 ± 0.05 μmol·L-1. The β-lactone ring unit of 1 is critical for its AChE inhibitory activity. The finding was further confirmed through exploring the interaction of 1 with AChE by molecular docking. In addition, both compounds 1 and 2 exhibited obvious antibacterial activity against Bacillus subtilis with a minimum inhibitory concentration (MIC) of 2 μg·mL-1. Compounds 3 and 4 exhibited antibacterial activities against Staphylococcus aureus with MICs of 4 and 2 μg·mL-1, respectively, which also exhibited DPPH radical scavenging activity comparable to the positive control with IC50 values of 9.2 ± 0.03 and 13.3 ± 0.01 μmol·L-1, respectively.

Secondary metabolites of endophyte fungi Xylaria sp. from Coptis chinensis / 中国中药杂志

Two new polyketides, lasobutone A(1) and lasobutone B(2), along with three known compounds, guignardianone C(3), guignardic acid(4), and 4-hydroxy-17R-methylincisterol(5), were isolated from the endophytic fungi Xylaria sp. by silica gel, MCI, and preparative HPLC, which was separated from the Chinese medicinal material Coptis chinensis and cultivated through solid fermentation with rice. Their structures were elucidated on the basis of spectroscopic methods, such as MS, NMR, IR, UV, and ECD. Compounds 2 and 4 showed inhibitory activities against the nitric oxide(NO) production in the LPS-induced macrophage RAW264.7 with IC_(50) values of 58.7 and 42.5 μmol·L~(-1) respectively, while compound 5 exhibited cytotoxic activities against HT-29 with IC_(50) value of 14.3 μmol·L~(-1).

Scanning Electron Microscopy (SEM) investigation of Polystyrene damage due to colonization by locally isolated Xylaria sp

@#<p style="text-align: justify;"><strong>BACKGROUND AND OBJECTIVES</strong>: Colonization of microorganisms on pollutants is the first indication of the potential ability of microbes to utilize plastic pollutants as a carbon source by sequential biodegradation into usable form for sustenance. The Philippines is considered the third highest country contributing to global mismanaged plastic waste. To locally manage and find a natural and innovative solution to this worldwide concern, this study aimed to evaluate the capacity of Xylaria sp. SDM (sterile dark mycelia) wild type, which was previously reported to colonize polyethylene plastic and mutant strains to colonize polystyrene, a plastic pollutant widely produced in the world. Assessment of the ability of local Xylaria sp. strains to grow, penetrate, and damage the surface and inner structures of polystyrene was investigated using scanning electron microscopy (SEM).</p><p style="text-align: justify;"><strong>METHODOLOGY:</strong> Xylaria sp. strains were cultured in a pH 5.0 mineral medium with 0.5% glucose as carbon source and polystyrene as a co-carbon source, and stored at 25?C for 50 days. At the end of the incubation period, due to irremovable fungal strains on the surface of the polystyrene strips, samples of polystyrene from each strain were subjected to SEM.</p><p style="text-align: justify;"><strong>RESULTS:</strong> On the 20th day of incubation, the presence of mucilaginous sheaths and fungal growth was observed on the surface of treated polystyrene strips. At the end of the 50-day incubation period, scanning electron microscopy (SEM) confirmed fungal growth and colonization, through the presence of mycelial mats and hyphae, of the wild type and mutant strains on the surface and inner structures of polystyrene except the control. Moreover, physical surface damage in the form of holes, cracks, and crevices on polystyrene demonstrated the active burrowing action of Xylaria sp. strains further supporting the potential of this fungus to damage polystyrene plastic.</p><p style="text-align: justify;"><strong>CONCLUSION:</strong> Whereas fungal growth on a polymer surface is necessary but not sufficient to conclude the process of carbon assimilation as the final biodegradation step, the initial colonization of Xylaria sp. strains on polystyrene supports its ability to establish itself and physically damage the pollutant. Hence, this study extended the existing knowledge on the colonizing ability of Xylaria sp. on plastic making it a potential candidate organism to biodegrade plastic waste, which is one of the topmost environmental waste hazards in the world today.</p>

Determination of Three Components in Xylaria Nigripes Powder by HPLC / 中国药师

Objective:To establish a HPLC method for the simultaneous determination of adenosine,genistein and 5-hydroxymel-lein in Xylarin nigripes powder.Methods:The chromatographic separation was carried out on a Pntulips@BP-C18column (250 mm× 4.6 mm,5 μm) at 35℃. The mobile phase consisted of acetonitrile-0.1% formic acid with gradient elution at a flow rate of 1.0 ml ·min-1,and the detection wavelength was 254 nm. Results:The linear range of adenosine was 0.162-1.62 μg(r=0.999 2). The average recovery was 98.12% and the RSD was 1.32% (n=6). The linear range of genistein was 0.02-0.2 μg(r=0.999 9). The average recovery was 98.89% and the RSD was 1.10% (n =6). The linear range of 5-hydroxymellein was 0.022-0.22 μg(r =0.999 9). The average recovery was 99.87% and the RSD was 0.98% (n=6). Conclusion:The method can be used to determine the contents of adenosine,genistein and 5-hydroxymellein,which provides the basis for the quality control and the further research of Xylaria nigripes.

Antibacterial, antifungal and cytotoxic activities exhibited by endophytic fungi from the Brazilian marine red alga Bostrychia tenella (Ceramiales)

Abstract Marine environment is one of the most important sources regarding natural products research. Besides, marine microorganisms have been denominated as a talented natural source for discovery of new leads. Although the association of macroalgae and fungi has been described regarding ecological issues, there is a lack of studies about marine seaweed endophytic fungi. In this context, the goal of this study was to evaluate cytotoxic, antifungal and antibacterial activities of endophytic fungi isolated from the Brazilian marine seaweed Bostrychia tenella (J.V. Lamouroux) J. Agardh (Ceramiales, Rhodophyta). Forty-five endophytic microorganism strains were isolated from B. tenella. Crude extracts and organic fractions of ten selected strains were obtained after growth in rice medium. Samples were evaluated for cytotoxicity, antifungal and antibacterial assays. Penicillium strains showed positive results in a diversity of assays, and other five strains were active in at least one test. In addition, cytochalasin D was isolated from Xylaria sp. This alga is composed of a microbiological potential, since its endophytic strains exhibited remarkable biological properties. Moreover, cytochalasin D isolation has confirmed chemical potential of marine endophytic strains. This is the first study in which cultured fungi isolates from the Brazilian macroalga B. tenella were evaluated concerning biological properties. Results corroborated that this species could be a pharmaceutical source from marine environment. Furthermore, Acremonium implicatum is being firstly described as marine endophyte and Xylaria sp., Trichoderma atroviride and Nigrospora oryzae as marine seaweed endophytes. Thus, this work reports the first study relating detailed isolation, cultivation and biological evaluation (cytotoxic, antifungal and antibacterial) of endophytes Penicillium decaturense and P. waksmanii from the Brazilian marine red alga B. tenella. We are also reporting the isolation of cytochalasin D, a known antitumor and antibiotic compound, from Xylaria sp. strain. Despite widespread prevalence in terrestrial and marine habitats, this present work describes the first occurrence of cytochalasin D as a metabolite from marine seaweed endophyte.

Metabolites of endophytic fungus Xylaria sp. with biological activities / 中国药学杂志

OB JECTIVE: To investigate the chemical constituents from the fermented rice substrate of endophytic fungus Xylaria sp. HCCB03890. METHODS: The compounds were isolated with silica gel column chromatography and reversed-phase high performance liquid chromatography. The structures of these compounds were elucidated through MS and NMR spectroscopic analysis. The anti-microbes activities were evaluated by disk diffusion method, cytotoxic activities were determined by MTT method, and anti-HIV activities were measured by using a firefly luciferase assay system. RESULTS: Six compounds were isolated and identified as TV-acetyltyra-mine(1), schizostatin(2), piliformic acid(3), stigmast-5,22-dien-3-ol(4), dankasterone(5) and demethylincisterol(6) on the basis of spectroscopic data analyses. Compound 3 showed moderate anti-microbial activity. Compounds 4-6 exhibited cytotoxic and anti-HIV activities, especially, and compund 5 and 6 showed significant anti-HIV activities with IC50 values of 0.4 and 0.9 μg · mL, respectively. CONCLUSION: Compounds 2, 5 and 6 were for the first time isolated from Xylaria sp., moreover, 5 and 6 are for the first time found in terrestrial microbes.

Vainillas colombianas y su microbiota. II. Diversidad, cultivo y microorganismos endófitos / Colombian Vanilla and its microbiota. II. Diversity, culture and endophytic microorganisms Abstract / Baunilhas colombianas e sua microbiótica. II. Diversidade, cultivo e microrganismos endófitos

La vainilla es la única especie como producto comestible entre las orquídeas. Su cultivo en Colombia se está promoviendo como alternativa a los tradicionales; especialmente entre pequeños y medianos agricultores. El cultivo actual adolece de una angosta base genética y por lo tanto es susceptible al estrés biótico, especialmente el causado por virus y hongos. Las vainillas silvestres son posible fuente de variabilidad que podría ayudar a ampliar su acervo genético y a su vez, podrían aportar microorganismos endófitos naturalmente asociados a ellas que tuviesen propiedades como antagonistas de los patógenos de la vainilla cultivada. En este estudio, se evidenció el conocimiento del cultivo de la vainilla como la diversidad del género Vanilla en Colombia. Como resultado de esta primera fase de investigación, se encontraron: veinte especies de vainillas colombianas y más de 60 morfoespecies de microorganismos endófitos. Se discutió la relevancia de estos hallazgos y su posible impacto en la promoción del cultivo de la vainilla, así como también se planteó el uso de estas plantas como un grupo modelo en investigación básica.

Among orchids, vanilla is the only species that is an edible product. Its farming is being promoted in Colombia as an alternative to traditional crops, especially among small and medium farmers. Existing crops have a limited genetic base and are therefore susceptible to biotic stress, particularly those caused by viruses and fungi. Wild vanilla can be a source of variability that could help increase its gene pool and could also provide naturally associated endophyte microorganisms with antagonistic properties to fight pathogens of farmed vanilla. In this study we assessed the understanding of vanilla cultivation as well as the diversity of the genus Vanilla in Colombia. As a result of this first phase of research, we found twenty species of Colombian vanilla and 60 morphospecies of endophytic microorganisms. We discuss the relevance of these findings and their potential impact on promoting vanilla farming, and also discussed the use of these plants as a model group for basic research.

A baunilha é a única espécie de produto comestível entre as orquídeas. O seu cultivo em Colômbia está sendo promovido como alternativa aos tradicionais; especialmente entre pequenos e médios agricultores. O cultivo atual carece de uma forte base genética, portanto é suscetível ao estrese biótico, especialmente causados por vírus e fungos. As baunilhas silvestres são uma possível fonte de variabilidade que poderia ajudar a ampliar o acervo genético e a sua vez, poderiam contribuir com microrganismos endófitos naturalmente associados a elas que tivessem propriedades como antagonista dos patógenos da baunilha cultivada. Neste estudo, se evidenciou o conhecimento do cultivo da baunilha como a diversidade do género Baunilha em Colômbia. Como resultado desta primeira fase de investigação, se encontraram: vinte espécies de baunilhas colombianas e mais de 60 morfoespecies de microrganismos endófitos. Discutiu-se a relevância destes resultados e o seu possível impacto na promoção do cultivo da baunilha, assim como também se evidenciou o uso destas plantas como um grupo modelo em investigação básica.

Chemical Constituents of the Fruiting Body of Xylaria polymorpha

Xylaria, belonging to the Ascomycotina, is known to produce diverse classes of bioactive substances. In an effort to identify the chemical constituents of the fruiting bodies of Xylaria polymorpha, linoleic acid (1), linoleic acid methyl ester (2), ergosterol (3), 4-acetyl-3,4-dihydro-6,8-dihydroxy-3-methoxy-5-methyl-1H-2-benzopyran-1-one (4), and 4-hydroxyscytalone (5) were isolated from its methanolic extract. Their structures were assigned on the basis of various spectroscopic studies.

New Record of Xylaria persicaria on Liquidambar Fruits in Korea

Some Xylaria materials growing on the fruits of Liquidambar spp. were collected. They were identified as X. persicaria on the basis of morphological characteristics and sequence analysis of the complete ITS region (ITS1-5.8S-ITS2) of rDNA. This is the first record of this species from Korea.

Taxonomical Characteristics of Xylaria spp. Collected from Malaysia

Five species of the genus Xylaria are recognized on Malaysia materials: X. hypoxylon (L. FR.) Grev., X. allantoidea (Berk.) Fr., X. cubensis (Mont.) Fr., X. curta Fr. and X. grammica (Mont.) Fr.. The collection of Xylaria allantoidea from Malaysia is compared to the collection from Taiwan in morphological characters. The species are described their the host and cultural characteristics by a bright microscope and a scanning electron microscope.