[Show abstract][Hide abstract] ABSTRACT: Phoma cyperi sp.nov. is described as a new pathogen of Cyperus iria L. It differed characteristically in culture, conidiomata, abortive cells, chlamydospores, and dictyochlamydospores from four closely related species of Phoma. Phoma cyperi showed specificity towards nut sedges and produced at least one phytotoxin. Key words: Phoma cyperi sp.nov., Cyperus iria, new pathogen, chlamydospore, dictyochlamydospore, phytotoxin.
Preview · Article · Feb 2011 · Canadian Journal of Botany
[Show abstract][Hide abstract] ABSTRACT: Ascochyta cypericola sp.nov., causing leaf blight of purple nutsedge in India, is described and illustrated. Key words: mycoherbicide, purple nutsedge, fungal pathogen.
No preview · Article · Feb 2011 · Canadian Journal of Botany
[Show abstract][Hide abstract] ABSTRACT: Microbial biodiversity provides an increasingly important source of medically and industrially useful compounds. We have isolated 14 actinomycete species from a collection of approximately 300 plant stem samples from the upper Amazonian rainforest in Peru. All of the cultured isolates produce substances with inhibitory activity directed at a range of potential fungal and bacterial pathogens. For some organisms, this activity is very broad in spectrum while other organisms show specific activity against a limited number of organisms. Two of these organisms preferentially inhibit bacterial test organisms over eukaryotic organisms. rDNA sequence analysis indicates that these organisms are not equivalent to any other cultured deposits in GenBank. Our results provide evidence of the untapped biodiversity in the form of biologically active microbes present within the tissues of higher plants.
No preview · Article · Mar 2009 · Microbial Ecology
[Show abstract][Hide abstract] ABSTRACT: Hair width and surface scale patterns (morphological characteristics) of hair from 21 selected species representing seven orders of mammals from the western United States were studied using scanning electron microscopy (SEM). The orders studied were Artiodactyla, Carnivora, Chiroptera, Didelphimorphia, Insectivora, Lagomorpha and Rodentia. Hair width, scale length and height, scale patterns, and scale position in relation to the shaft were used to characterize differences in morphology for both the species and orders. Specimens were taken from the dorsal scapular region and the centres of hair shafts of mature mammals were used for images. A key (identification chart) was created to characterize each species. These studies suggest that morphological differences in guard hair and underfur could provide a useful atlas for forensics, taxonomy and archaeology.
No preview · Article · Jan 2009 · Journal of Natural History
[Show abstract][Hide abstract] ABSTRACT: The endophytic fungus Chloridium sp. produces javanicin under liquid and solid media culture conditions. This highly functionalized naphthaquinone exhibits strong antibacterial activity against Pseudomonas spp., representing pathogens to both humans and plants. The compound was crystallized and the structure was elucidated by X-ray crystallography. The X-ray structure confirms the previously elucidated structure of the compound that was done under standard spectroscopic methods. The importance of javanicin in establishing symbiosis between Chloridium sp. and its host plant, Azadirachta indica, is briefly discussed.
Full-text · Article · Dec 2008 · Current Microbiology
[Show abstract][Hide abstract] ABSTRACT: Colletotrichum dematium is an endophytic fungus recovered from a Pteromischum sp. growing in a tropical forest in Costa Rica. This fungus makes a novel peptide antimycotic, colutellin A, with a MIC of 3.6 microg ml(-1) (48 h) against Botrytis cinerea and Sclerotinia sclerotiorum. Collutellin A has a mass of 1127.7 Da and contains residues of Ile, Val, Ser, N-methyl-Val and beta-aminoisobutryic acid in nominal molar ratios of 3 : 2 : 1 : 1 : 1, respectively. Independent lines of evidence suggest that the peptide is cyclic and sequences of Val-Ile-Ser-Ile and Ile-Pro-Val have been deduced by MS/MS as well as Edman degradation methods. Colutellin A inhibited CD4(+) T-cell activation of interleukin 2 (IL-2) production with an IC(50) of 167.3+/-0.38 nM, whereas cyclosporin A in the same test yielded a value of 61.8 nM. Inhibition of IL-2 production by collutellin A at such a low concentration indicates the potential immunosuppressive activity of this compound. In repeated experiments, cyclosporin A at or above 8 microg ml(-1) exhibited high levels of cytotoxicity on human peripheral blood mononuclear cells, whereas collutellin A or DMSO (carrier) alone, after 24 and 48 h of culture, exhibited no toxicity. Because of these properties collutellin A has potential as a novel immunosuppressive drug.
[Show abstract][Hide abstract] ABSTRACT: Muscodor crispans (isolate B-23) is described as a new species of Muscodor. It is an anamorphic sterilia endophytic fungus residing within the stem tissues of Ananas ananassoides, a wild pineapple in the Bolivian Amazon Basin. This strain is characterized by the production of a pinkish felt-like mycelium on potato dextrose agar (PDA) and other media under lighted conditions, but developing a whitish mycelium in the dark. The fungus produces no fruiting structures or spores of any kind when incubated on multiple synthetic or natural media. On PDA and other common laboratory media, its hyphae develop into regular undulating patterns and associated with them are cauliflower-like structures (3.5-14 μm). Analysis of the volatile organic compounds it produces in culture by GC/MS showed that M. crispans primarily produces a number of esters, alcohols, and small molecular weight acids, but no naphthalene or azulene derivatives as other members of this genus. The volatiles possess antibiotic properties making this organism potentially useful in a number of situations. A molecular genetic analysis of the ITS1, 5.8S rDNA, and ITS2 regions showed 100% similarity to Muscodor albus. Muscodor albus, M. roseus and M. vitigenus are each genetically related to xylariaceous taxa by virtue of ca. 95% sequence similarity to this group. Justification for the designation of a new species is primarily based on the novel phenotypic characters of isolate B-23 including its peculiar hyphal growth patterns (undulating hyphae), its
reddish pigment production in the light, the odd cauliflower-like structures associated with its hyphae, and its unusual gaseous products. In spite of its 100% genetic similarity to the rDNA regions of M. albus, this organism is considered distinct because of the number and kind of its unusual phenotypic characteristics. The rDNA sequence data obtained represents well less than 1% of the total DNA of a fungus.
[Show abstract][Hide abstract] ABSTRACT: Oidium sp. has been recovered as an endophyte in Terminalia catappa (tropical chestnut) in Costa Rica. The volatile organic compounds (VOCs) of this organism uniquely and primarily consist of esters of propanoic acid, 2-methyl-, butanoic acid, 2-methyl-, and butanoic acid, 3-methyl-. The VOCs of Oidium sp. are slightly inhibitory to many plant pathogenic fungi. Previous work on the VOCs of Muscodor albus demonstrated that besides esters of small organic acids, a small organic acid and a naphthalene derivative were needed to obtain maximum antibiotic activity. Thus, the addition of exogenous volatile compounds such as isobutyric acid and naphthalene, 1,1'-oxybis caused a dramatic synergistic increase in the antibiotic activity of the VOCs of Oidium sp. against Pythium ultimum. In fact, at elevated concentrations, there was not only 100% inhibition of P. ultimum but killing as well. In addition, a coculture of Muscodor vitigenus (making only naphthalene) and Oidium sp. plus isobutyric acid produced an additive antibiosis effect against P. ultimum. The biological implications of multiple volatile compounds acting to bring about antibiosis in nature are discussed.
[Show abstract][Hide abstract] ABSTRACT: Phomodione, [(4aS(*),9bR(*))-2,6-diacetyl-7-hydroxy-4a,9-dimethoxy-8,9b-dimethyl-4a.9b-dihydrodibenzo[b,d]furan-1,3(2H,4H)-dione], an usnic acid derivative, was isolated from culture broth of a Phoma species, discovered as an endophyte on a Guinea plant (Saurauia scaberrinae). It was identified using NMR, X-ray crystallography, high resolution mass spectrometry, as well as infrared and Raman spectroscopy. In addition to phomodione, usnic acid and cercosporamide, known compounds with antibiotic activity, were also found in the culture medium. Phomodione exhibited a minimum inhibitory concentration of 1.6 microg/mL against Staphylococcus aureus using the disk diffusion assay, and was active against a representative oomycete, ascomycete and basidiomycete at between three and eight micro-grams per mL.
[Show abstract][Hide abstract] ABSTRACT: Three novel endophytic streptomycetes have been isolated and characterized from plants with ethnobotanical uses on the Malay Peninsula including: Thottea grandiflora (family -Aristolochiaceae), Polyalthia spp. (family -Annonaceae), and Mapania sp. (family -Cyperaceae). Each isolate, as studied by scanning electron microscopy, has small hyphae, and produces typical barrel-shaped spores arising by hyphal fragmentation. Interestingly, although none has any detectable antibacterial killing properties, each has demonstrable killing activity against one or more pathogenic fungi including organisms such as Phytophthora erythroseptica, Pythium ultimum, Sclerotinia sclerotiorum, Mycosphaerella fijiensis and Rhizoctonia solani. Molecular biological studies on the rRNA gene sequence of each isolate revealed that it is distinct from all other genetic accessions of streptomyectes in GenBank, and each bears some genetic similarity to other streptomycetes. The bioactivity of each microbe was extractable in various organic solvents.
Full-text · Article · Oct 2007 · FEMS Microbiology Letters
[Show abstract][Hide abstract] ABSTRACT: 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.
[Show abstract][Hide abstract] ABSTRACT: Endophytic streptomycetes have been isolated and characterized from several species of Nothofagus and other plants growing in the southern reaches of Patagonia. No endophytic streptomycete was obtained from any plant species studied in Northern Patagonia. However, from Southern Patagonia, biologically active Streptomyces spp. from several plant species were isolated. Each isolate, as studied by scanning electron microscopy (SEM), has small hyphae, some produce typical barrel-shaped spores in culture and each has some unique hyphal surface structures. Interestingly, although none has any detectable antibacterial killing properties, each has demonstrable killing activity against one or more pathogenic fungi including representative plant pathogenic organisms such as Phytophthora erythroseptica, Pythium ultimum, Sclerotinia sclerotiorum, Mycosphaerella fijiensis, and Rhizoctonia solani. The 16S rDNA sequences of the isolates were distinct from all other genetic accessions of Streptomyces in GenBank. However, isolate C-2 from Chiliotrichum diffusum (Compositae) is identical, in all respects, to isolate C-4 obtained from Misodendrum punctulatum (Loranthaceae). These results confirm that endophytic streptomycetes represent a novel source of biologically active microorganisms.
No preview · Article · Feb 2007 · Microbial Ecology
[Show abstract][Hide abstract] ABSTRACT: Factors affecting hardness of canned Great Northern beans (Phaseolus vulgaris, L.) were investigated. Addition of calcium significantly increased the hardness of processed beans; however, the calcium content usually found in hard culinary water supplies did not cause good quality beans to be unacceptably hard when processed. Firmer processed beans had a higher calcium uptake and lower water absorption. Sucrose increased the hardness of processed beans. Sucrose and calcium were synergistic in their firming action. Beans stored at high temperature and humidity for a prolonged period of time became firmer when processed and more sensitive to calcium hardening and to the synergistic effects of calcium and sucrose.
No preview · Article · Aug 2006 · Journal of Food Science
[Show abstract][Hide abstract] ABSTRACT: Muscodor albus is an endophytic fungus of tropical tree species that produces volatile organic compounds (VOC's) that have antibiotic activity. A new isolate of this organism has been obtained from a small, unidentified vine, generally used by the indigenous people of the Tesso Nilo region in Central Sumatra, Indonesia, to treat snakebites. This unique organism produces a number of VOC's not previously observed in other M. albus isolates including tetrohydofuran, 2-methyl furan; 2-butanone; aciphyllene, and large amounts of an unusual azulene derivative. Noticeably absent from the VOC mixture was 1-butanol, 3-methyl-. Scanning electron micrographs of the organism showed a unique fishnet-like deposit of what appears to be a biopolymer covering the hyphae. The ITS-5.8S rDNA partial sequence data showed 99% identity to the original M. albus strain cz-620. In addition, an artificial mixture of some of the VOC's produced by this new isolate generally mimicked the inhibitory as well as lethal effects of the fungal VOC's on the test microorganisms. One of the most sensitive test fungi was Stachybotrys chartarum, an organism associated with the “toxic mold” syndrome of buildings. Fungi belonging to the Muscodor genus regularly appear in tropical rainforests throughout the world and these isolates appear to have chemical, biological, and structural characteristics that make them potentially useful in medicine, agricultural and industrial applications.
[Show abstract][Hide abstract] ABSTRACT: Soils of all types and locations have generally served as the major sources of streptomycetous bacteria. These organisms are the source of nearly 80% of the world's antibiotics. Now, it is realized that Streptomyces spp. (within the group of prokaryotic filamentous bacteria known as actinomycetes) can exist as endophytes within the interstices of some higher plants. While it is sometimes possible to isolate one or two different streptomycetes from certain plants, most plants are free of these organisms. However, the snakevine (Kennedia nigricans) of the Northern Territory of Australia has yielded at least 39 different endophytic actinomycetes (95% of them being Streptomyces spp.) Most of these isolates possessed no detectable antibiotic properties, while at least seven had antibacterial and antifungal activities. Examination of eight selected cultures by scanning electron microscopy (SEM) as well as environmental scanning electron microcopy (FEI ESEM FEG) (FEI Company, Hillsobro, Ore., USA) revealed unusual patterns, structures, and features of the spores and hyphae of these microorganisms. For instance, as revealed by ESEM FEG for the first time, it has become obvious that extremely fine hair-like structures (average 25-49 nm with gold-coated specimens) exist on the spores and hyphae of some endophytic streptomycetes. The biological purpose of these hair-like protrusions is unknown. Both SEM and ESEM FEG can be effectively used as tools in identification and elucidation of the biology of these organisms. In addition, unusual colony morphology, observed with the unaided eye can very easily be used to distinguish some of these isolates since characteristic donut and pseudo-horn shaped colonies appeared in culture.
[Show abstract][Hide abstract] ABSTRACT: Muscodor albus, an endophytic fungus originally isolated from Cinnamomum zeylanicum, produces a mixture of volatile organic compounds (VOCs) in culture and its spectrum of antimicrobial activity is broad. Using the original isolate of M. albus as a selection tool, it has been possible to find other culturally and biochemically unique wild-type isolates of this organism existing as endophytes in a variety of other plant species, including Grevillea pterifolia (fern-leafed grevillea), Kennedia nigriscans (snake vine) and Terminalia prostrata (nanka bakarra) growing in the northern reaches of the Northern Territory of Australia. Interestingly, none of the new isolates had a culture morphology that was identical to the original isolate, nevertheless each possessed hyphal characteristics that resembled that isolate. Furthermore, their ITS-5.8S rDNA sequences were 96-99 % identical to that of M. albus and the isolates were considered M. albus on the basis of the DNA sequence data. However, the VOCs produced by these new isolates greatly differed in quality from the original strain by virtue of the production of naphthalene, naphthalene, 1,1'-oxybis-, and one or more other compounds. In bioassays with a range of test micro-organisms, including fungi and bacteria, each isolate possessed biological activity but the range of activity was great. Artificial mixtures of some of the VOCs mimicked the effects of the VOCs of the fungus. The value of these observations to the biology and practical uses of M. albus in agriculture and other applications is discussed.
[Show abstract][Hide abstract] ABSTRACT: Coronamycin is a complex of novel peptide antibiotics with activity against pythiaceous fungi and the human fungal pathogen Cryptococcus neoformans. It is also active against the malarial parasite, Plasmodium falciparum, with an IC(50) of 9.0 ng ml(-1). Coronamycin is produced by a verticillate Streptomyces sp. isolated as an endophyte from an epiphytic vine, Monstera sp., found in the Manu region of the upper Amazon of Peru. Bioassay-guided fractionation of the fermentation broths of this endophyte on silica gel and HPLC chromatography yielded two principal, inseparable, peptides with masses of 1217.9 and 1203.8 Da. Three other minor, but related components, are also present in the preparation. Amino acid analysis of coronamycin revealed residues of component 1, component 2, methionine, tyrosine and leucine at a ratio of 2:2:1:1:3. Other compounds with antifungal activities are also produced by this endophytic streptomycete.
[Show abstract][Hide abstract] ABSTRACT: An endophytic isolate of Gliocladium sp. was obtained from the Patagonian Eucryphiacean tree—Eucryphia cordifolia, known locally as “ulmo”. The fungus was identified on the basis of its morphology and aspects of its molecular biology. This fungus produces a mixture of volatile organic compounds (VOC's) lethal to such plant pathogenic fungi as Pythium ultimum and Verticillum dahliae, while other pathogens were only inhibited by its volatiles. Some of the same volatile bioactive compounds exuded by Gliocladium sp. such as 1-butanol, 3-methyl-, phenylethyl alcohol and acetic acid, 2-phenylethyl ester, as well as various propanoic acid esters, are also produced by Muscodor albus, a well known volatile antimicrobial producer. In fact, M. albus was used as a selection tool to effectively isolate Gliocladium sp. since it is resistant to VOC's produced by M. albus. However, the primary volatile compound produced by Gliocladium sp. is 1,3,5,7-cyclooctatetraene or annulene, which by itself, was an effective inhibitor of fungal growth. The authenticated VOC's of Gliocladium sp. were inhibitory to all, and lethal to some test fungi in a manner that nearly mimicked the gases of Gliocladium sp. itself. This report shows that the production of selective volatile antibiotics by endophytic fungi is not exclusively confined to the Muscodor spp.
[Show abstract][Hide abstract] ABSTRACT: An endophytic fungus, Pestalotiopsis theae strain CTC5, was isolated from the cambium of Cinnamomum iners at the Siri Rukhachat Medicinal Plant Garden, Salaya campus of Mahidol University, Nakornprathom, Thailand. By regular scanning electron microscopy (SEM), a spheroid-like extension of this fungus appears on the three relatively long appendages that occur on each conidium. The isolate CTC5, also frequently produces the basal appendage with the small knob at the end. The high similarities of ITS1, 5.8S rDNA and ITS2 sequences strongly confirmed that the isolate CTC5 should be classified as Pestalotiopsis theae by virtue of 99.63% homology. Pestalotiopsis theae is commonly known as a pathogen on leaves of Thea sinnensis and other plants. The combination of classical and molecular phylogenic classification may contribute a better understanding of evolutionary relationships among Pestalotiopsis isolates from diverse places and help explain relationships to their host plants. Furthermore, the new technique of environmental scanning electron microscopy is used herein to show the slimy nature of the conidiospores and that these appendages cannot be seen while the spores are in the acervulus.