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PubMed2005

The causal agents of damping-off disease of buglosse from Iran.

Iran is considered a major genetic for medicinal plant in the world. Because of this significant diversity and historical background in identification and utilization to remedy human and animal diseases, export of medicinal plant can help to strengthen local as well as natural economy. Buglosse (Fig. 1) is one of the most important and common medicinal plants in Iran and exist as Echium amoneum and Borago officinalis. This work was conducted in order to identify the causal agent(s) of damping off disease in buglosse. Plant disease samples were taken from Esfahan and Tehran provinces. Symptoms on original plant including root, crown rot, dark tissue, pith and hallow root were collected in order to isolate disease agent(s). Symptomatic root and crown tissues after surface sterilization with 96% ethanol were transferred on to PDA and WA media and also on moist filter paper in petri dishes. Two fungal colonies grew from tissue segments and spore culture was subsequently purified. The fungal isolate identified as Rhizoctonia solani based on the following test. Hyphal tip was removed from colony margin placed on PDA and PSA media and incubated in dark. Colony diameter of one hundred hyphae measured and nucleus was stained according to Bandoni (1979), Kronland and Stanghellini (1988). It was observed that in each cell of hyphae there are more than two nuclei. Single spore culture were obtained from macroconidia of Fusarium isolate. After 24 hr of incubation, growing single spore were transferred to KCL medium to detect spore chains. Fungal isolates transferred to PSA and PDA media for sporulation. After 7 days colonies appeared as white cream to pinkish on top and cream to dark pink at the bottom of petri dish with abundant micro and macro conidia. Colonies were snow white, felting shape, with ample causal hyphae on PSA medium. On KCL medium, fungal growth was superficial and colonies were colorless with long macroconidia and individual sausage-shape macroconidia being thinner one side and having maximum four septa. Microconidia were long double compartment round on both side, straight to slightly curved. Base on morphology and dimension of conidia and production of chlamidospore the funguses identify as Fusarium solani.

Borago↗
PubMed2006

[Micromorphological features of Pleurotus pulmonarius (Fr.) Quel. and P. ostreatus (Jacq.) P. Kumm. strains in pure and binary culture with yeasts].

Micromorphology of oyster mushrooms Pleurotus ostreatus (Jacq.) Quel. and P. pulmonarius (Fr.) Quel. was studied in pure and binary culture with yeasts (Cryptococcus laurentii 1629, Rhodotorula minuta 2790, Sporidiobolus salmonicolor (see text for symbol) 31A-11, Candida krusie 3452, Pichia holstii 3438). The cultures were cultivated on malt-agar and water agar. Various mycelial structures were described: strands, rings, thin searching mycelium, clamps, crystals, head-like offshoots, mycelial fragments, chlamydospores, and coralloid hyphae. Vegetative mycelia interact in different ways (forming anastomoses, strands, system of thin anucleate hyphae) within the same culture. Head-like offshoots of mycelial cells, previously regarded as spores of asexual reproduction, appeared to lack nuclei and to be filled with polyphosphates. Coralloid hyphae, which induce yeast cell lysis after direct contact, were detected only in binary culture with yeasts under condition of nitrogen deficit. The same way of feeding is typical for carnivorous mushrooms.

Agar↗
PubMed2006

[Isolation and phylogenetic analysis of one actinomycete strain YIM 90022 exhibiting anticancer activity].

One facultative alkaliphilic actinomycete strain YIM 90022 was isolated from hypersaline alkaline soil in Qinghai province, China. An almost-complete 16S rRNA gene sequence (1500 bp) for strain YIM 90022 was obtained. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM 90022 was closely related to four members of the genus Nocardiopsis with 16S rRNA gene sequence similarity values of 98.8% (N. exhalans DSM 44407T), 98.5% (N. prasina DSM 43845T), 98.4% (N. metallicus DSM 44598T) and 97.8% (N. listeri DSM 40297T), but represented a distinct phylogenetic lineage. Repetitive element sequence-based PCR (rep-PCR) genomic fingerprinting was evaluated on strain YIM 90022 and its closest relatives to investigate their genetic relatedness. The analysis of the rep-PCR genomic fingerprints showed that strain YIM 90022 was distinguishable from its closest relatives. The polyphasic taxonomic data presented in this study, including its morphology, physiological and biochemical characteristics, chemotaxonomy, 16S rRNA gene sequence-based phylogenetic analysis and rep-PCR genomic fingerprinting, supported the view that strain YIM 90022 represented a potential new species of the genus Nocardiopsis. The fermentation broth of strain YIM 90022 strongly inhibited growth of cell series of gastric cancer, lung cancer, mammary cancer, melanoma cancer, renal cancer and uterus cancer. Strain YIM 90022 grew well on most tested media, producing exuberant vegetative hyphae and aerial hyphae. The vegetative hyphae are long and fragmented. Light yellow to deep brown diffusible pigments were produced on ISP 2, ISP 3 and ISP 6. Growth of the strain occurred in the pH range 6.0-12.0, with optimal pH8.5. The NaCl tolerate range was 0-15% (W/V). Cell walls contain meso-diaminopimelic acid and have no diagnostic sugars. Polar lipids are phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylmethylethanolamine. Major menaquinones are MK-10 (H4, H6). The DNA G + C content is 71.5 mol %.

Actinobacteria↗
PubMed1991

Colonization of Ascaris lumbricoides eggs by the fungus Verticillium chlamydosporium Goddard.

The process of colonization of Ascaris lumbricoides eggs by the fungus Verticillium chlamydosporium was studied by scanning electron microscopy. The preparations were made by fractionation of egg suspension exposed to the fungus for four days and frozen in liquid nitrogen according to Stĕrba and Milácek (1986). Ovicidal fungus forms an abundant ramifying mycelial network in the area between the eggs. However, egg-shells are penetrated only by some hyphae without any penetration organs produced (simple hyphal penetration). In a liquid medium, after penetration, hyphae inside the eggs rapidly grow among inner structures of egg-shells and on the surface of developing larvae. In the next phase, hyphae colonize the developing larva. The eggs attacked by this fungus remain morphologically unchanged for a long time except the sites of penetration. Verticillium chlamydosporium is a fungus with unique ovicidal properties. It colonizes the eggs of Ascaris lumbricoides at all stages of embryo development and also attacks larvae inside the eggs.

Animals↗
PubMed1989

Taxonomic clarification of Cladosporium trichoides Emmons and its subsequent synonyms.

Cladosporium trichoides Emmons has been treated by some mycologists as a synonym of Cladosporium bantianum (Sacc.) Borelli and has been transferred to the genus Xylohypha (Fr.) Mason. In the present study, a herbarium specimen of C. bantianum (Torula bantiana Sacc.) Borelli, prepared by Saccardo, was compared with a herbarium specimen and a living type culture of C. triochoides by light and scanning electron microscopy (SEM) and was found to be dissimilar. Herbarium specimens and living cultures of Xylohypha nigrescens, the type species of the genus Xylohypha, were also compared with those of C. trichoides and other pathogenic Cladosporium species. Fundamental differences were found between X. nigrescens and Cladosporium species, in colony morphology, manner of sporulation and conidial morphology. All Cladosporium isolates produced olive-black colonies regardless of environmental conditions, bore brown pigment on the walls of the vegetative hyphae as well as on the walls of the fruiting structures and produced branched chains of conidia either from well differentiated or poorly differentiated conidiophores, or directly from the hyphae. By SEM, conidia showed strong to moderately protruded hila, and the basal contour of the conidia was always truncated. On germination, hyphal tubes were produced randomly from the surface of the conidia. In contrast, X. nigrescens produced white colonies with or without brown centres, depending on the culture medium, bore pigment on the conidial walls and on conidiogenous cells but not on the vegetative hyphae and produced infrequently branched conidial chains, usually from intercalary conidiogenous cells which were globose to hat-shaped. Conidial hila were nonprotruding but, instead, were deeply concave and pore-like. The basal contour of the conidia was round and germ tubes were produced only from the pore-like hila. These results indicate that C. triochoides Emmons is different from C. bantianum (Sacc.) Borelli and that the reclassification of C. trichoides into the genus Xylohypha was not warranted.

Animals↗
PubMed1988

Ultrastructural localization of anionic sites on the surface of yeast, hyphal and germ-tube forming cells of Candida albicans.

The cell wall of Candida albicans contains chitin, beta-glucans and phosphorylated mannoproteins, and possesses a fuzzy coat which is thought to play a role in pathogenicity, phagocytosis, and adherence of this dimorphic yeast. Using scanning electron microscopy and the gold method, mannoproteins were detected on the whole surface of blastoconidia including the bud scars, but chitin was absent even after alpha-mannosidase treatment of the cells. The presence of surface beta-(1----6)glucan (but not beta(1----3)glucan) was observed only after extensive alpha-mannosidase and alkaline phosphatase treatments of blastoconidia. Using transmission and scanning electron microscopy, the locations of anionic sites were revealed by polycationic colloidal gold-chitosan complexes on the surface of blastoconidia, germ tubes and hyphae. Anionic sites were dispersed evenly over the surface of blastoconidia bearing bud scars. Depending upon the growth conditions, anionic sites could be detected on emerging buds and young cells. However, bud scars were always free of marking. When germ-tube formation was induced, anionic sites were present at different densities on all cell surfaces, the highest density being observed on cells with bud scars. Anionic sites were detected at a remarkably high density on all hyphal surfaces. An apical concentration of anionic sites was observed on germ tubes and hyphae. The distribution of anionic sites was not modified by endoglucosaminidase treatment of blastoconidia, germ tubes and hyphae. The anionic sites were associated with the fuzzy coat. As the hyphal form is regarded as possessing the greatest invasiveness, it is suggested that anionic sites play an important role in establishing tissue colonization by this human pathogen.

Anions↗
PubMedDate not supplied

Fine structure of vegetative mycelium and spores of Nocardia spp.

The fine structure of a fragmenting and sporulating mycelium of cultures of actinomycetes possessing biochemical properties characteristic of the genus Nocardia--a cell wall of type IV and lipid LCN a--was studied. It was found that fragmenting hyphae are similar in structure to the vegetative hyphae of known actinomycetes. Sporulation takes place through the simultaneous division of a sporulating hypha by numerous septa. Spores differ from vegetative cells in the presence of a thickened electron-dense cell wall, dense internal contents, and the presence of vacuoles.

Microscopy, Electron↗
PubMed1977

Changes in the surface layer (sheath) of the cell wall of streptomycetes during sporulation.

Fine structural changes of the sheath, occurring during spore formation in strains Streptomyces finlayi ATCC 23 340 and Streptomyces coeruleorubidus FBUA 328 were investigated by means of electron microscopy of air-dried whole mounts and thin sections. The results suggest that in the strains the process of sporulation is not strictly synchronized spatially with the molecular arrangements and re-arrangements (formation of hairy or spiny surface ornaments) occurring outside the wall of the sporulation hyphae, in the sheath. On the contrary, the intensity of transformation induction in the sheath may show a gradually decreasing tendency from the tip of the sporulating hypha towards its sterile basal part, resulting in the formation of both ornamented and smooth spores in the same chain. This suggests that the morphogenetic changes occurring in the sheath during spore formation are probably controlled by a "functional centre", located near the tip of the sporulating hypha, and this centre is perhaps indentical with the cell unit at the tip.

Cell Wall↗
PubMed1980

Balanced growth and morphogenesis of Histoplasma capsulatum in a defined synthetic medium.

We have characterized balanced growth of yeast and hyphal cells of Histoplasma capsulatum and cells during transition from yeast to hyphae in a newly developed synthetic medium, R3B3. Homogeneous populations of yeast at 37 degrees C and hyphae at 25 degrees C grew in this medium with generation times of 10h and 19h, respectively. The growth rates were exponential, as demonstrated by the kinetics of net increase in dry weight. Identical rates of net increase were observed for ribonucleic acid (RNA) and protein, indicating conditions which approached steady state growth. In addition, this defined medium facilitated incorporation of radioactive precursors into RNA and protein and thus will allow for future detailed studies of macromolecular synthesis. When the incubation temperature of growing yeast cells was switched from 37 degrees C to 25 degrees C, the growth rate decreased as indicated in the generation time (19 h). Although the kinetic rates of RNA and protein synthesis also decreased, these rates were slightly faster relative to that observed for the increase in dry weight. During the later stage(s) of the yeast to hyphae transition a marked increase and subsequent decrease was observed for both RNA and protein. After this period of time, the synthesis of RNA and protein proceeded at the steady state rates usually observed in hyphal cultures.

Cell Count↗
PubMed1994

Systemic phaeohyphomycosis caused by Xylohypha bantiana in a dog.

An 8-year-old, Maltese-cross bitch presented with chronic neck and back pain and an acute onset of circling, hyperaesthesia and constant crying. Clinical examination revealed temporal muscle atrophy, an abnormal hanging reflex, cervical rigidity and severe hepatomegaly. Ultrasonography of the liver showed several disseminated, poorly demarcated, hypoechoic areas which on fine needle aspirates, contained large numbers of pigmented fungal hyphae. Cerebrospinal fluid examination revealed fungal hyphae and numerous Ehrlichia canis morulae. A diagnosis of systemic phaeohyphomycosis secondary to ehrlichiosis was proposed. Treatment was unsuccessful and the dog was euthanased. At necropsy, multiple yellowish-green to black, necro-granulomatous foci were found throughout the liver parenchyma and similar foci were present in the spleen, renal cortices and adrenal glands. Irregular, multifocal, grey to black foci of malacia were present in both the grey and the white matter of the brain. On histopathological examination pigmented fungal hyphae were demonstrated in the liver, spleen, kidneys, portal lymph node and adrenals, as well as in the brain. Cultures of various organs yielded a fungal organism identified as Xylohypha bantiana.

Animals↗
PubMedDate not supplied

[New applications of submicroscopic techniques in the study of biodegradation caused by lichen thalli].

The advances that have been made on the effect of lichens on rock substrate have been numerous. The first techniques used in order to know the type of biodeterioration produced by lichen thalli, were observations by light microscopy. The microchemical techniques that followed this, such as X-Ray Diffraction and Infrared Spectroscopy, provided knowledge of the mineral composition of the substrate which is in contact with the lichen thalli. This zone is known as interface. More recently, the Scanning Electron-Microscope has allowed observations of the relationship between the hyphae of the lower part of the thallus and the topography of the superficial part of the rock. In the current work, new applications of Scanning Electron Microscopy are presented. The backscattered electron image permits observation of the penetration of living thalli elements in the rock. With this technique, it is possible to follow the fissures underneath the lichen thalli and see at a cellular level the biological elements. This technique is an important step in understanding the biodeterioration produced by lichens. It allows clarification of such aspects as the ability of embedded minerals detached from the rock among the hyphae and also the possibility of investigating organic and inorganic compounds mixed with hyphae and algae. This technique, moreover, is promising for use in future investigations of biodeterioration where the cellular morphology of the different organisms are interesting, taking into account treatments with biocides.

Biodegradation, Environmental↗
PubMedDate not supplied

[Electron microscopic structure of the mycelium of Actinomyces chrysomallus, the producer of the antibiotic chrysomallin, during the stab fermentation process].

Ultrastructural changes in the mycelium of Actinomyces (Streptomyces) chrysomallus 2703 producing the antibiotic chrysomallin in the process of submerged fermentation are described. When the antibiotic was produced at a high rate, most hyphae remained viable for a long period of time and had the ultrastructure typical of the young cells of actinomycetes. At the same time, a number of degenerative changes due to aging were observed; these resulted in autolysis. A decrease in the antibiotic titre was accompanied with intensive sporulation in a considerable number of the submerged hyphae. Structural changes in the sporeforming hyphae distinctly differed from those in the vegetative ones: the cell walls became thicker and numerous septa were formed. The exogenous formation of submerged spores in the culture under study has been studied in detail for the first time.

Culture Media↗
PubMed1996

[Acute appendicitis caused by mucorales in a patient with severe aplastic anemia: report of an autopsy case].

A male patient with severe aplastic anemia was admitted for bone marrow transplantation. While waiting for a donor, high doses of methylprednisolone, anabolic steroid and granulocyte colony stimulating factor were given without response. Deferoxamine was administered for prophylaxis of hemochromatosis because of high level of ferritin. Acute right lower abdominal pain and pyrexia developed. A diagnosis of acute appendicitis was made and appendectomy was performed. The histopathological examination of the resected appendix revealed necrotizing hemorrhagic appendicitis with numerous hyphae of Mucorales. Though anti-fungal agent (amphotericin B) administration was continued, he subsequently developed ileo-cecal abscess and eventually died due to myoglobinuric nephropathy caused by extensive necrosis of the iliopsoas muscle. Autopsy revealed dissemination of hyphae of Mucorales in lungs, kidneys, large vessels and muscle of the bilateral lower limbs. Systemic vascular invasion and embolization of fungal hyphae were also observed. However, culture of exudate sampled from ileocecum yielded no Mucorales. It was emphasized that antemortem diagnosis and effective anti-fungal treatments are essential for the management of intestinal mucormycosis. The relation ship between mucormyocosis and deferoxamine was also discussed.

Acute Disease↗
PubMed1998

Fontana-Masson--stained tissue from culture-proven mycoses.

BACKGROUND: The Fontana-Masson stain can be used to detect melanin of dematiaceous fungi such as Curvularia lunata and Bipolaris hawaiiensis in tissue. This stain is often used to identify fungi that may not have an evident brown color in hematoxylin-eosin-stained sections. However, it is not clear whether hyphae of nondematiaceous fungi can be stained with the Fontana-Masson procedure. METHODS: Paraffin sections from culture-proven mycoses caused by species of Aspergillus, Candida, Fusarium, Pseudallescheria, Trichosporon, zygomycetes, and dematiaceous fungi were stained by the Fontana-Masson procedure. Extent of stain intensity and its distribution in fungal elements in tissue were evaluated by means of an intensity scale based on Cryptococcus neoformans as a positive control. RESULTS: Many Aspergillus spp, some zygomycetes, and all of the dematiaceous fungi showed strong intensity, whereas other fungi showed either weak intensity or no staining. CONCLUSION: Fungal hyphae other than dematiaceous fungi occasionally can be stained with the Fontana-Masson procedure. The morphology of positively stained hyphae must be carefully evaluated, especially when they are hyaline in hematoxylin-eosin-stained tissue sections.

Aspergillus↗
PubMed2002

Morphological alterations induced by cold-shock in Neurospora crassa.

The effects of cold-shock on Neurospora crassa was here investigated. In cold-shock treated hyphae (6 h at 4 degrees C) the branching pattern was changed and dichotomy as well as a fan-like-pattern structure were temporarily detected at the tips. When exogenous Ca(2+) (500 mM) was added to the hyphae, these morphological alterations were not detected. In addition, the protein electrophoretic profile of cultures submitted to cold-shock was different from that of cultures kept at 30 degrees C. After 1 and 2 hours at 4 degrees C at least 5 bands were more intense than at 30 degrees C. The results suggest that cold-shock temporarily increases the synthesis of some proteins probably involved in the acclimatization process at 4 degrees C, and that the effects on morphology are probably due to damage to calcium influx.

Calcium↗
PubMed2002

Estimation of hyphal tensile strength in production-scale Aspergillus oryzae fungal fermentations.

Fragmentation of filamentous fungal hyphae depends on two phenomena: hydrodynamic stresses, which lead to hyphal breakage, and hyphal tensile strength, which resists breakage. The goal of this study was to use turbulent hydrodynamic theory to develop a correlation that allows experimental data of morphology and hydrodynamics to be used to estimate relative (pseudo) tensile strength (sigma(pseudo)) of filamentous fungi. Fed-batch fermentations were conducted with a recombinant strain of Aspergillus oryzae in 80 m(3) fermentors, and measurements were made of both morphological (equivalent hyphal length, L) and hydrodynamic variables (specific power input, epsilon; kinematic viscosity, v). We found that v increased over 100-fold during these fermentations and, hence, Kolmogorov microscale (lambda) also changed significantly with time. In the impeller discharge zone, where hyphal fragmentation is thought to actually take place, lambda was calculated to be 700-3500 microm, which is large compared to the size of typical fungal hyphae (100-300 microm). This result implies that eddies in the viscous subrange are responsible for fragmentation. Applying turbulent theory for this subrange, it was possible to calculate sigma(pseudo)from morphological and hydrodynamic measurements. Pseudo tensile strength was not constant but increased to a maximum during the first half and then decreased during the second half of each fermentation, presumably due to differences in physiological state. When a literature correlation for hyphal fragmentation rate (k(frag)) was modified by adding a term to account for viscosity and tensile strength, the result was better qualitative agreement with morphological data. Taken together, these results imply hyphal tensile strength can change significantly over the course of large-scale, fed-batch fungal fermentations and that existing fragmentation and morphology models may be improved if they accounted for variations in hyphal tensile strength with time.

Aspergillus oryzae↗
PubMed2001

Intra-particle oxygen diffusion limitation in solid-state fermentation.

Oxygen limitation in solid-state fermentation (SSF) has been the topic of modeling studies, but thus far, there has been no experimental elucidation on oxygen-transfer limitation at the particle level. Therefore, intra-particle oxygen transfer was experimentally studied in cultures of Rhizopus oligosporus grown on the surface of solid, nutritionally defined, glucose and starch media. The fungal mat consisted of two layers--an upper layer with sparse aerial hyphae and gas-filled interstitial pores, and a dense bottom layer with liquid-filled pores. During the course of cultivation ethanol was detected in the medium indicating that oxygen was depleted in part of the fungal mat. Direct measurement of the oxygen concentrations in the fungal mat during cultivation, using oxygen microelectrodes, showed no oxygen depletion in the upper aerial layer, but revealed development of steep oxygen concentration gradients in the wet bottom layer. Initially, the fungal mat was fully oxygenated, but after 36.5 hours oxygen was undetectable at 100 microm below the gas-liquid interface. This was consistent with the calculated oxygen penetration depth using a reaction-diffusion model. Comparison of the overall oxygen consumption rate from the gas phase to the oxygen flux at the gas-liquid interface showed that oxygen consumption of the microorganisms occurred mainly in the wet part of the fungal mat. The contribution of the aerial hyphae to overall oxygen consumption was negligible. It can be concluded that optimal oxygen transfer in SSF depends on the available interfacial gas-liquid surface area and the thickness of the wet fungal layer. It is suggested that the moisture content of the matrix affects both parameters and, therefore, plays an important role in optimizing oxygen transfer in SSF cultures.

Aerobiosis↗
PubMed2002

Regulators of GTP-binding proteins cause morphological changes in the vacuole system of the filamentous fungus, Pisolithus tinctorius.

Tubule formation is a widespread feature of the endomembrane system of eukaryotic cells, serving as an alternative to the better-known transport process of vesicular shuttling. In filamentous fungi, tubule formation by vacuoles is particularly pronounced, but little is known of its regulation. Using the hyphae of the basidiomycete Pisolithus tinctorius as our test system, we have investigated the effects of four drugs whose modulation, in animal cells, of the tubule/vesicle equilibrium is believed to be due to the altered activity of a GTP-binding protein (GTP gamma S, GDP beta S, aluminium fluoride, and Brefeldin A). In Pisolithus tinctorius, GTP gamma S, a non-hydrolysable form of GTP, strongly promoted vacuolar tubule formation in the tip cell and next four cells. The effects of GTP gamma S could be antagonised by pre-treatment of hyphae with GDP beta S, a non-phosphorylatable form of GDP. These results support the idea that a GTP-binding protein plays a regulatory role in vacuolar tubule formation. This could be a dynamin-like GTP-ase, since GTP gamma S-stimulated tubule formation has only been reported previously in cases where a dynamin is involved. Treatment with aluminium fluoride stimulated vacuolar tubule formation at a distance from the tip cell, but NaF controls indicated that this was not a GTP-binding-protein specific effect. Brefeldin A antagonised GTP gamma S, and inhibited tubule formation in the tip cell. Given that Brefeldin A also affects the ER and Golgi bodies of Pisolithus tinctorius, as shown previously, it is not clear yet whether the effects of Brefeldin A on the vacuole system are direct or indirect.

Aluminum Compounds↗