RESUMEN
Two new species and a new combination of Hypoxylon from Texas were identified and described based on morphological, multigene phylogenetic (ITS [nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2], 28S [5' 1200 bp of nuc 28S rDNA], RPB2 [partial second largest subunit of the DNA-directed RNA polymerase II], TUB2 [partial ß-tubulin]), and chemotaxonomic data. Hypoxylon olivaceopigmentum is characterized by its pulvinate to glomerate stromata, olivaceous KOH-extractable pigments, equilateral ascospores, and indehiscent perispore. Hypoxylon texense can be distinguished from morphologically similar species by its rust to dark brick KOH-extractable pigments and the high-performance liquid chromatography (HPLC) profile of its stromatal secondary metabolites. Hypoxylon hinnuleum is proposed as the sexual morph of Nodulisporium hinnuleum, featuring dark vinaceous glomerate stromata with dark brick KOH-extractable pigments composed of cohaerin-type azaphilones and smooth equilateral ascospores with indehiscent perispore. Based on these diagnostic characters, H. hinnuleum forms a complex with H. croceum and H. minicroceum. More than 50 ITS sequences with high identity originating from North American and East Asian environmental isolates formed a well-supported clade with the type of N. hinnuleum, demonstrating the widespread distribution of the species complex. In addition, updated descriptions and comprehensive illustrations with detailed information on the diagnostic features of H. fendleri and H. perforatum are provided. The multilocus phylogenetic reconstruction of Hypoxylon supported the status of the new species and broadened the knowledge about intergeneric relationships.
Asunto(s)
Microbiología Ambiental , Filogenia , Esporas Fúngicas/citología , Xylariales/clasificación , Xylariales/aislamiento & purificación , Análisis por Conglomerados , ADN de Hongos/química , ADN de Hongos/genética , ADN Ribosómico/química , ADN Ribosómico/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Microscopía , Pigmentos Biológicos/análisis , ARN Polimerasa II/genética , ARN Ribosómico 28S/genética , Análisis de Secuencia de ADN , Texas , Tubulina (Proteína)/genética , Xylariales/genética , Xylariales/fisiologíaRESUMEN
A chemical study of the EtOAc extract of Nemania bipapillata (AT-05), an endophytic fungus isolated from the marine red alga Asparagopsis taxiformis - Falkenbergia stage, led to the isolation of five new botryane sesquiterpenes, including the diastereomeric pair (+)-(2R,4S,5R,8S)-(1) and (+)-(2R,4R,5R,8S)-4-deacetyl-5-hydroxy-botryenalol (2), (+)-(2R,4S,5R,8R)-4-deacetyl-botryenalol (3), one pair of diastereomeric botryane norsesquiterpenes bearing an unprecedented degraded carbon skeleton, (+)-(2R,4R,8R)-(4) and (+)-(2R,4S,8S)-(5), which were named nemenonediol A and nemenonediol B, respectively, in addition to the known 4ß-acetoxy-9ß,10ß,15α-trihydroxyprobotrydial (6). Their structures were elucidated using 1D and 2D NMR, HRESIMS and comparison with literature data of similar known compounds. The absolute configurations of 2, 3 and 4 were deduced by comparison of experimental and calculated electronic circular dichroism (ECD) spectra, while those of 1 and 5 were assigned from vibrational circular dichroism (VCD) data. Compound 4 weakly inhibited acetylcholinesterase, whereas compound 1 inhibited both acetylcholinesterase and butyrylcholinesterase. Compounds 1, 3, 5 and 6 were tested against two carcinoma cell lines (MCF-7 and HCT-116), but showed no significant citotoxicity at tested concentrations (IC50 > 50 µM).
Asunto(s)
Endófitos/aislamiento & purificación , Rhodophyta/microbiología , Terpenos/metabolismo , Xylariales/aislamiento & purificación , Acetilcolinesterasa/metabolismo , Espectroscopía de Resonancia Magnética con Carbono-13 , Inhibidores de la Colinesterasa/farmacología , Células HCT116 , Humanos , Células MCF-7 , Espectroscopía de Protones por Resonancia Magnética , Terpenos/química , Terpenos/aislamiento & purificaciónRESUMEN
Endophytic fungi belonging to Muscodor genus are considered as promising alternatives to be used in biological control due to the production of volatile organic compounds (VOCs). The strains LGMF1255 and LGMF1256 were isolated from the medicinal plant Schinus terebinthifolius and, by morphological data and phylogenetic analysis, identified as belonging to Muscodor genus. Phylogenetic analysis suggests that strain LGMF1256 is a new species, which is herein introduced as Muscodor brasiliensis sp. nov. The analysis of VOCs production revealed that compounds phenylethyl alcohol, α-curcumene, and E (ß) farnesene until now has been reported only from M. brasiliensis, data that supports the classification of strain LGMF1256 as a new species. M. brasiliensis completely inhibited the phytopathogen P. digitatum in vitro. We also evaluated the ability of VOCs from LGMF1256 to inhibit the development of green mold symptoms by inoculation of P. digitatum in detached oranges. M. brasiliensis reduced the severity of diseases in 77%, and showed potential to be used for fruits storage and transportation to prevent the green mold symptoms development, eventually reducing the use of fungicides.
Asunto(s)
Antifúngicos/farmacología , Agentes de Control Biológico/farmacología , Penicillium/efectos de los fármacos , Compuestos Orgánicos Volátiles/metabolismo , Compuestos Orgánicos Volátiles/farmacología , Xylariales/metabolismo , Anacardiaceae/microbiología , Antifúngicos/metabolismo , Agentes de Control Biológico/metabolismo , Fungicidas Industriales , Penicillium/crecimiento & desarrollo , Alcohol Feniletílico/metabolismo , Sesquiterpenos/metabolismo , Xylariales/aislamiento & purificaciónRESUMEN
ABSTRACT Anthracnose is a crop disease usually caused by fungi in the genus Colletotrichum or Gloeosporium. These are considered one of the main pathogens, causing significant economic losses, such as in peppers and guarana. The current forms of control include the use of resistant cultivars, sanitary pruning and fungicides. However, even with the use of some methods of controlling these cultures, the crops are not free of anthracnose. Additionally, excessive application of fungicides increases the resistance of pathogens to agrochemicals and cause harm to human health and the environment. In order to find natural antifungal agents against guarana anthracnose, endophytic fungi were isolated from Amazon guarana. The compounds piliformic acid and cytochalasin D were isolated by chromatographic techniques from two Xylaria spp., guided by assays with Colletotrichum gloeosporioides. The isolated compounds were identified by spectrometric techniques, as NMR and mass spectrometry. This is the first report that piliformic acid and cytochalasin D have antifungal activity against C. gloeosporioides with MIC 2.92 and 2.46 µmol mL-1 respectively. Captan and difenoconazole were included as positive controls (MIC 16.63 and 0.02 µmol mL-1, respectively). Thus, Xylaria species presented a biotechnological potential and production of different active compounds which might be promising against anthracnose disease.
Asunto(s)
Enfermedades de las Plantas/prevención & control , Xylariales/química , Paullinia/microbiología , Endófitos/química , Fungicidas Industriales/farmacología , Filogenia , Enfermedades de las Plantas/microbiología , Espectrometría de Masas , Xylariales/aislamiento & purificación , Xylariales/genética , Xylariales/metabolismo , Estructura Molecular , Colletotrichum/efectos de los fármacos , Colletotrichum/fisiología , Endófitos/aislamiento & purificación , Endófitos/genética , Endófitos/metabolismo , Fungicidas Industriales/aislamiento & purificación , Fungicidas Industriales/químicaRESUMEN
In 2010-2011, a Xylaria sp. was documented growing from seeds of both Chlorocardium rodiei and Chlorocardium venenosum, a commercially valuable timber in Guyana. We conducted extensive surveys in 2015-2016, where this Xylaria sp. was observed fruiting from ca. 80% of dispersed seeds in both natural and logged forests in the Upper Demerara-Berbice, Potaro-Siparuni, and the Cuyuni-Mazaruni districts of central Guyana. Species of Xylaria are ascomycetous fungi generally characterized by black, carbonaceous, multiperitheciate ascoma commonly found growing on dead wood. Combined teleomorphic and molecular data indicate that the fungus represents a novel species, described here as Xylaria karyophthora.
Asunto(s)
Lauraceae/microbiología , Semillas/microbiología , Xylariales/clasificación , Xylariales/aislamiento & purificación , Actinas/genética , Bosques , Guyana , Técnicas Microbiológicas , Microscopía , Filogenia , Reacción en Cadena de la Polimerasa , ARN Polimerasa II/genética , Análisis de Secuencia de ADN , Xylariales/citología , Xylariales/genéticaRESUMEN
Anthracnose is a crop disease usually caused by fungi in the genus Colletotrichum or Gloeosporium. These are considered one of the main pathogens, causing significant economic losses, such as in peppers and guarana. The current forms of control include the use of resistant cultivars, sanitary pruning and fungicides. However, even with the use of some methods of controlling these cultures, the crops are not free of anthracnose. Additionally, excessive application of fungicides increases the resistance of pathogens to agrochemicals and cause harm to human health and the environment. In order to find natural antifungal agents against guarana anthracnose, endophytic fungi were isolated from Amazon guarana. The compounds piliformic acid and cytochalasin D were isolated by chromatographic techniques from two Xylaria spp., guided by assays with Colletotrichum gloeosporioides. The isolated compounds were identified by spectrometric techniques, as NMR and mass spectrometry. This is the first report that piliformic acid and cytochalasin D have antifungal activity against C. gloeosporioides with MIC 2.92 and 2.46µmolmL-1 respectively. Captan and difenoconazole were included as positive controls (MIC 16.63 and 0.02µmolmL-1, respectively). Thus, Xylaria species presented a biotechnological potential and production of different active compounds which might be promising against anthracnose disease.
Asunto(s)
Endófitos/química , Fungicidas Industriales/farmacología , Paullinia/microbiología , Enfermedades de las Plantas/prevención & control , Xylariales/química , Colletotrichum/efectos de los fármacos , Colletotrichum/fisiología , Endófitos/genética , Endófitos/aislamiento & purificación , Endófitos/metabolismo , Fungicidas Industriales/química , Fungicidas Industriales/aislamiento & purificación , Espectrometría de Masas , Estructura Molecular , Filogenia , Enfermedades de las Plantas/microbiología , Xylariales/genética , Xylariales/aislamiento & purificación , Xylariales/metabolismoRESUMEN
A new species of Hypoxylon was discovered, based on material collected in French Guiana and recognised on the basis of new combination of morpholological characters in comparison with type and authentic material of macroscopically similar taxa. These findings were corroborated by the rather isolated positions of its ITS-nrDNA and beta-tubulin DNA sequences in molecular phylogenies. However, the most salient feature of this fungus only became evident by a comparison of its stromatal HPLC profile, revealing several secondary metabolites that were hitherto not observed in stromata of any other member of the Xylariaceae. Part of the stromata were subsequently extracted to isolate these apparently specific components, using preparative chromatography. Five metabolites were obtained in pure state, and their chemical structures were elucidated by means of high resolution mass spectrometry and nuclear magnetic resonance spectroscopy. They turned out to be tetramic acid derivatives of the so-called vermelhotin type. Aside from vermelhotin, previously isolated from cultures of endophytic fungi, we identified three novel congeners, for which the trivial names hypoxyvermelhotins A-C were proposed. Like vermelhotin, they constitute orange-red pigments and a preliminary biological characterisation revealed them to have rather strong cytotoxic and moderate to weak antimicrobial effects. These results further illustrate the high diversity of unique secondary metabolites in stromata of the hypoxyloid Xylariaceae, a family in which biological diversity seems to parallel the chemical diversity of their bioactive principles to a great extent.
Asunto(s)
Pigmentos Biológicos/análisis , Pigmentos Biológicos/química , Xylariales/química , Xylariales/clasificación , Cromatografía Líquida de Alta Presión , Análisis por Conglomerados , ADN de Hongos/química , ADN de Hongos/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Guyana Francesa , Datos de Secuencia Molecular , Estructura Molecular , Filogenia , Pirrolidinonas/análisis , Pirrolidinonas/química , Análisis de Secuencia de ADN , Tubulina (Proteína)/genética , Xylariales/genética , Xylariales/aislamiento & purificaciónRESUMEN
A Nodulisporium sp. (Hypoxylon sp.) has been isolated as an endophyte of Thelypteris angustifolia (Broadleaf Leaf Maiden Fern) in a rainforest region of Central America. It has been identified both on the basis of its morphological characteristics and by scanning electron microscopy as well as ITS sequence analysis. The endophyte produces volatile organic compounds (VOCs) that have both fuel (mycodiesel) and use for biological control of plant disease. When grown on potato dextrose agar, the organism uniquely produces a series of ketones, including acetone; 2-pentanone; 3-hexanone, 4-methyl; 3-hexanone, 2,4- dimethyl; 2-hexanone, 4-methyl, and 5-hepten, 2-one and these account for about 25% of the total VOCs. The most abundant identified VOC was 1,8 cineole, which is commonly detected in this group of organisms. Other prominent VOCs produced by this endophyte include 1-butanol, 2- methyl, and phenylethanol alcohol. Moreover, of interest was the presence of cyclohexane, propyl, which is a common ingredient of diesel fuel. Furthermore, the VOCs of this isolate of Nodulisporium sp. were selectively active against a number of plant pathogens, and upon a 24 h exposure caused death to Phytophthora palmivora, Rhizoctonia solani, and Sclerotinia sclerotiorum and 100% inhibition to Phytophthora cinnamomi with only slight to no inhibition of the other pathogens that were tested. From this work, it is becoming increasingly apparent that each isolate of this endophytic Nodulisporium spp., including the Daldina sp. and Hypoxylon spp. teleomorphs, seems to produce its own unique set of VOCs.
Asunto(s)
Endófitos/aislamiento & purificación , Endófitos/metabolismo , Helechos/microbiología , Compuestos Orgánicos Volátiles/metabolismo , Xylariales/aislamiento & purificación , Xylariales/metabolismo , Antiinfecciosos/metabolismo , América Central , Análisis por Conglomerados , Medios de Cultivo/química , ADN de Hongos/química , ADN de Hongos/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Endófitos/clasificación , Endófitos/citología , Microscopía , Datos de Secuencia Molecular , Filogenia , Análisis de Secuencia de ADN , Xylariales/clasificación , Xylariales/citologíaRESUMEN
Thirteen endophytic fungal strains of the genus Pestalotiopsis were isolated from the medicinal plant Maytenus ilicifolia Mart. ex. Reiss (commonly known as "espinheira santa") and their antimicrobial properties were investigated. Two isolates were successful in inhibiting the growth of the tested microorganisms (Escherichia coli, Klebsiella pneumoniae, Micrococcus luteus, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus (MRSA)) using the technique of bioautographic thin-layer chromatography (TLC) agar overlay assay. An analysis based on a polyphasic approach integrating taxonomic information, morphological traits, RAPD markers, and the sequencing of the ITS1-5.8S-ITS2 of the rDNA led to the assignment of the isolates as belonging to the species Pestalotiopsis microspora, Pestalotiopsis vismiae, and Pestalotiopsis leucothoes. Therefore, the present study presents a new approach to the study of endophytic fungi of the genus Pestalotiopsis.
Asunto(s)
Antibiosis , Maytenus/microbiología , Plantas Medicinales/microbiología , Xylariales/clasificación , Xylariales/aislamiento & purificación , Antibacterianos/farmacología , Bacterias/crecimiento & desarrollo , Teorema de Bayes , Brasil , Cromatografía en Capa Delgada , ADN de Hongos/análisis , ADN Espaciador Ribosómico/análisis , Pruebas de Sensibilidad Microbiana/métodos , Datos de Secuencia Molecular , Técnicas de Tipificación Micológica , Filogenia , Técnica del ADN Polimorfo Amplificado Aleatorio , Análisis de Secuencia de ADN , Xylariales/crecimiento & desarrolloRESUMEN
Muscodor albus is an endophytic fungus, represented by a number of isolates from tropical tree and vine species in several of the world's rainforests, that produces volatile organic compounds (VOCs) with antibiotic activity. A new isolate, E-6, of this organism, with unusual biochemical and biological properties, has been obtained from the branches of a mature Guazuma ulmifolia (Sterculiaceae) tree growing in a dry tropical forest in SW Ecuador. This unique organism produces many VOCs not previously observed in other M. albus isolates, including butanoic acid, 2-methyl-; butanoic acid, 3-methyl-; 2-butenal, 2-methyl-; butanoic acid, 3-methylbutyl ester; 3-buten-1-ol, 3-methyl; guaiol; 1-octene, 3-ethyl-; formamide, N-(1-methylpropyl); and certain azulene and naphthalene derivatives. Some compounds usually seen in other M. albus isolates also appeared in the VOCs of isolate E-6, including caryophyllene; phenylethyl alcohol; acetic acid, 2-phenylethyl ester; bulnesene; and various propanoic acid, 2-methyl- derivatives. The biological activity of the VOCs of E-6 appears different from the original isolate of this fungus, CZ-620, since a Gram-positive bacterium was killed, and Sclerotinia sclerotiorum and Rhizoctonia solani were not. Scanning electron micrographs of the mycelium of isolate E-6 showed substantial intertwining of the hyphal strands. These strands seemed to be held together by an extracellular matrix accounting for the strong mat-like nature of the mycelium, which easily lifts off the agar surface upon transfer, unlike any other isolate of this fungus. The ITS-5.8S rDNA partial sequence data showed 99 % similarity to the original M. albus strain CZ-620. For the first time, successful establishment of M. albus into its natural host, followed by recovery of the fungus, was accomplished in seedlings of G. ulmifolia. Overall, isolates of M. albus, including E-6, have chemical, biological and structural characteristics that make them potentially useful in medicine, agricultural and industrial applications.
Asunto(s)
Antibacterianos/biosíntesis , Malvaceae/microbiología , Xylariales/aislamiento & purificación , Xylariales/metabolismo , Ascomicetos/efectos de los fármacos , Bacillus subtilis/efectos de los fármacos , ADN de Hongos/química , ADN de Hongos/genética , ADN Espaciador Ribosómico/genética , Ecuador , Escherichia coli/efectos de los fármacos , Genes de ARNr , Hifa/ultraestructura , Microscopía Electrónica de Rastreo , Datos de Secuencia Molecular , Filogenia , ARN de Hongos/genética , ARN Ribosómico 5.8S/genética , Rhizoctonia/efectos de los fármacos , Análisis de Secuencia de ADN , Árboles , Xylariales/química , Xylariales/crecimiento & desarrolloRESUMEN
Six xylariaceous fungi, including two Hypoxylon taxa and four Nemania taxa, are described as new. They were collected from either Costa Rica or Taiwan. Two of the Nemania species--N. flavitextura and N. primolutea--were cultured and typical Geniculosporium anamorphs were produced.
Asunto(s)
Xylariales/clasificación , Xylariales/aislamiento & purificación , Costa Rica , Microscopía , Microscopía de Interferencia , Fotograbar , Fotomicrografía , Esporas Fúngicas/citología , Taiwán , Xylariales/citología , Xylariales/crecimiento & desarrolloRESUMEN
Podosordaria mexicana Ellis & Holway é pela primeira vez citada para o Brasil. Trata-se de um fungo da familia Xylariaceae comumente encontrado sobre fezes de burro, coelho, vaca e cavalo. Esta espécie se distingue das demais pelo estroma obcónico e curto-estipitado e pelo tamanho dos seus ascosporos. As outras espécies curto-estipitadas possuem ascosporos pequenos. Os espécimens estudados estäo depositados no Herbário do Departamento de Micología da Universidade Federal de Pernambuco (URM) sob n§ 73600 e 74489 respectivamente, coletadas no município de Agrestina - PE, no ano de 1977