Science.gov

Sample records for deuteromycota hyphomycetes conidia

  1. Impact of two treatments of a formulation of Beauveria bassiana (Deuteromycota: Hyphomycetes) conidia on Varroa mites (Acari: Varroidae) and on honeybee (Hymenoptera: Apidae) colony health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bee colonies in southern France were treated with conidia from 2 strains of Beauveria bassiana – one commercial (GHA) and the other isolated from Varroa mites in the region (Bb05002). Objectives were to evaluate treatment effect on colony weight, adult bee mass, capped brood, and on Varroa fall onto...

  2. Impact of two treatments of a formulation of Beauveria bassiana (Deuteromycota: Hyphomycetes) conidia on Varroa mites (Acari: Varroidae) and on honeybee (Hymenoptera: Apidae) colony health.

    PubMed

    Meikle, William G; Mercadier, Guy; Holst, Niels; Girod, Vincent

    2008-12-01

    Bee colonies in southern France were treated with conidia (asexual spores) from two strains of Beauveria bassiana, an entomopathogenic fungus. One strain was commercial (GHA) and the other had been isolated from Varroa mites in the region (Bb05002). Objectives were to evaluate treatment effect on colony weight, adult bee mass, capped brood, and on Varroa fall onto sticky boards. Treatments included conidia formulated with either carnauba or candelilla wax powder, candelilla wax powder alone, or control; in two treatment groups formulation was applied a second time after one week. Treatment did not affect colony health. Colonies treated twice with Bb05002 conidia and carnauba wax powder had significantly higher mite fall compared to colonies treated with blank candelilla wax powder. The proportion of fallen mites that were infected in both conidia treatments was higher than controls for 18 days after the second treatment. The number of fungal propagules on the bees themselves remained elevated for about 14 days after the second treatment. These results were compared to published results from previous experiments with regard to infection duration. PMID:18506583

  3. Bioassay assessment of metarhizium anisopliae (metchnikoff) sorokin (deuteromycota: hyphomycetes) against Oncometopia facialis (signoret) (hemiptera: cicadellidae)

    PubMed Central

    Pria Júnior, Wolney Dalla; Lacava, Paulo Teixeira; Messias, Claudio Luiz; Azevedo, João Lúcio; Lacava, Pedro Magalhães

    2008-01-01

    Citrus Variegated Chlorosis (CVC) is an economically important, destructive disease in Brazil and is caused by Xylella fastidiosa and transmitted by sharpshooter insects. In this study, the efficacy of the fungus Metarhizium anisopliae in controlling the sharpshooter Oncometopia facialis was studied by bioassay conditions. In the bioassay, insects were sprayed with a suspension containing 5 X 107 conidia mL-1. Adults captured in the field were treated in groups of 10 in a total of 11 replications per treatment. Significant differences between the natural mortality and the mortality of insects treated with the fungus were observed 6 days after inoculations (P<0.05). These significant differences increased until 10 days after treatment. The fungus caused 87.1% mortality, with the LT50 varying from 5 to 6 days. The LC50 was 1.2 X 106 conidia mL-1, varying from 7.7 X 105 to 2 X 106 conidia mL-1. The results showed that the sharpshooter O. facialis was susceptible to the entomopathogenic action of M. anisopliae in controlled condition during bioassay. PMID:24031192

  4. Variability in susceptibility to simulated sunlight of conidia among isolates of entomopathogenic Hyphomycetes.

    PubMed

    Fargues, J; Goettel, M S; Smits, N; Ouedraogo, A; Vidal, C; Lacey, L A; Lomer, C J; Rougier, M

    1996-09-01

    The influence of simulated sunlight on survival of conidia of 4 species of entomopathogenic Hyphomycetes was investigated. Conidia from 65 isolates ofBeauveria bassiana, 23 ofMetarhizium anisopliae, 14 ofMetarhizium flavoviride and 33 isolates ofPaecilomyces fumosoroseus were irradiated by artificial sunlight (295 to 1,100 nm at an ultraviolet-B irradiance of 0.3 W m(-2)) for 0, 1, 2, 4 and 8 h. Survival was estimated by comparing the number of colony forming units (CFU) produced by conidia exposed to irradiation to the number of CFUs produced by an unexposed control. Survival decreased with increased exposure to simulated sunlight; exposure for 2 h or more was detrimental to all isolates tested. Overall, isolates ofM. flavoviride were the most resistant to irradiation followed byB. bassiana andM. anisopliae. Conidia ofP. fumosoroseus were most susceptible. In addition to the large interspecies differences in susceptibility to irradiation, there was also an intraspecies variation indicating that strain selection to irradiation tolerance may be important in the development of microbial control agents where increased persistence in an insolated environment is desirable. PMID:20882453

  5. Hyphomycetes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hyphomycetes are anamorphic forms of ascomycetes or basidiomycetes. In many instances, teleomorphs appear to have been lost over evolutionary time. They are identified on the basis of conidial shape and color, number and position of conidial septa, degree of aggregation of conidiophores, and mode ...

  6. Effects of UVB irradiance on conidia and germinants of the entomopathogenic Hyphomycete Metarhizium anisopliae: a study of reciprocity and recovery.

    PubMed

    Braga, G U; Flint, S D; Messias, C L; Anderson, A J; Roberts, D W

    2001-02-01

    We tested the effects of irradiances of 920 and 1200 mW m-2 (weighted irradiance) on the conidia and germinants of the entomopathogenic Hyphomycete Metarhizium anisopliae. The conidia were exposed to the two irradiances for 1, 2, 4, 6, 7 or 8 h. Increased exposure decreased relative percent culturability. The inactivation provoked by the irradiance of 1200 mW m-2 was higher than for the 920 mW m-2, with a reduction in the 50% lethal time (LT50) from 6 h 40 min to 4 h 26 min. Reciprocity was not observed when conidia in water suspension and germinants in different stages of the germinative process were exposed to a 17.3 kJ m-2 total dose at both irradiance levels. Although nonreciprocity was observed in all situations, its magnitude varied as a function of metabolic state and/or cell-cycle phase in which the conidia were at the exposure time. The least difference between the effects of the two irradiance levels was observed when nongerminating conidia in suspension were exposed, and the greatest was observed when conidia were exposed during an advanced germination phase. Doses of 6.6 and 17.3 kJ m-2 supplied through the two irradiance levels delayed the germination of the surviving conidia. At both doses, delay was greater during exposure to the higher irradiance. Nonreciprocity was higher for the 17.3 kJ m-2 dose. Nonreciprocity magnitude, in addition to depending on the conidial physiological state, also depended on dose. The results demonstrate the importance of evaluating the impact of the increase in irradiance during the different stages of the fungal life cycle, especially during the stages which are more sensitive to UV, and not simply in dormant conidia. PMID:11272727

  7. Impact of a treatment of Beauveria bassiana (Deuteromycota: Hyphomycetes) on honeybee (Hymenoptera: Apidae) colony health and on varroa mites (Acari: Varroidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2 field experiments bee colonies in southern France were treated with conidia of an isolate of Beauveria bassiana collected from varroa mites in the region. The main objectives were to evaluate the effect of treatment on colony growth, on total adult bee weights, on the amounts of sealed brood an...

  8. Effects of temperature and solar radiation interactions on the survival of quiescent conidia of the entomopathogenic hyphomycetePaecilomyces fumosoroseus (Wize) Brown and Smith.

    PubMed

    Smits, N; Fargues, J; Rougier, M; Goujet, R; Itier, B

    1996-09-01

    The detrimental effect of solar radiation on the survival of conidia of the entomopathogenic fungusPaecilomyces fumoroseus was studied by monitoring germinability and ability to form colonies (CFU) of conidia irradiated at two temperatures, 25 and 35 °C, harmless to shaded conidia. There was no apparent effect when spores were exposed to a high level of artificial radiation (0.66 W m(-2) UVB). However, at a lower level of irradiance (0.33 W m(-2)), effects of radiation occurred more quickly at 35 °C than at 25 °C. Under natural solar radiation, the rate of decrease in germinability or viability was doubled at 35 °C as compared to 25 °C, indicating an interaction between temperature and radiation effects under natural conditions. This interaction was not detected in indoor experiments, indicating that the spectral distribution of UV radiation has to be taken in account as well as its irradiance when studying its effects. PMID:20882452

  9. Method for Determining the best Hydrophilic-lipophilic Balance (HLB) Number of a Compatible Non-ionic Surfactant in Formulation Development for Areal Conidia of Metarhizium anisopliae (Deuteromycotina: Hyphomycetes)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A non-swirling/direct dropping method was developed to optimize a compatible, non-ionic surfactant for formulation development of Metarhizium anisopliae conidia by determining the optimal hydrophilic-lipophilic balance number. Results showed the optimal HLB number of the tested M. anisopliae conidia...

  10. Aquatic hyphomycetes in polluted groundwater habitats of central Germany.

    PubMed

    Krauss, G; Sridhar, K R; Jung, K; Wennrich, R; Ehrman, J; Bärlocher, F

    2003-05-01

    Polluted groundwater wells located in a former copper shale mining district (11 sites; Mansfelder Land, Central Germany) and in meadows of the Mulde and Elbe rivers (2 sites) were assessed for occurrence and species richness of aquatic hyphomycetes. Water temperatures at all sites were relatively low and fluctuated less than in surface waters. Oxygen concentrations were always below saturation, whereas sulfate, nitrate, and phosphate levels reached extremely high values in several of the wells. Relatively high levels of Pb, Mn, and Fe were found in some of the wells, but overall few concentrations of individual metals and metalloids exceeded European guidelines for drinking water. Pollen tube growth inhibition, used to assess cytotoxicity of the water, ranged between 4 and 50%. Between 1 and 10 distinct species of aquatic hyphomycetes colonized sterile Alnus glutinosa leaves exposed at the Mansfelder Land sites; for the meadow sites, 8-20 species were found. Heliscus lugdunensis and Anguillospora sp. were the two most widespread species. Fungal colonization occurred much more slowly than in surface water, as demonstrated by scanning electron microscopy and the release of conidia from recovered leaves. The conidial output from exposed alder leaves ranged from 0.2 to 95 conidia mg (-1) dry mass, corresponding to 10% of the values for contaminated surface waters in the same region. Overall, groundwater appears to be a marginal habitat for aquatic hyphomycetes, but may nevertheless play a vital role as long-term reservoir facilitating rapid recolonization following a collapse in fungal communities in surface waters. PMID:12704555

  11. Evaluation of Beauveria bassiana (Balsamo) Vuillemin (Deuteromycota: Hyphomycetes) strains isolated from varroa mites in southern France

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Entomopathogenic fungi are currently being considered as alternatives to chemical pesticides for controlling varroa mites of honey bees. Varroa mites were collected from 112 beehives in southern France and evaluated for the presence of entomopathogenic fungi. Eight strains of Beauveria bassiana we...

  12. [Method of biological control of Triatominae, vectors of Chagas disease, using entomopathogenic Hyphomycetes. Preliminary study].

    PubMed

    Romaña, C A; Fargues, J; Pays, J F

    1987-01-01

    Bioassays determined the pathogenic activity of 14 strains of 5 entomopathogenic hyphomycetous species (Fungi imperfecti), Beauveria bassiana, Beauveria brongniartii, Metarhizium anisopliae, Nomuraea rileyi and Paecilomyces fumosoroseus to Rhodnius prolixus. Treatments consisted of direct spraying with conidial titrated suspensions on first instar larvae. When tested at 3 X 10(5) conidia/cm2, only 2 strains, B. bassiana n. 297 and B. bassiana n. 326 killed 100% of larvae at 10 days post-exposure. In the same time their LD50 and their LD90 did not differ significantly. After 3 weeks, the mortality caused by either dose of spores of B. bassiana n. 297 was very high. In contrast, in the case of B. bassiana n. 326 mortality due to reduced doses remained at low rates. This laboratory study demonstrated that the isolate, B. bassiana n. 297 might have potential as microbial control agent against the assassin bugs. PMID:3111731

  13. Adhesion of Nongerminated Botrytis cinerea Conidia to Several Substrata †

    PubMed Central

    Doss, Robert P.; Potter, Sandra W.; Chastagner, Gary A; Christian, James K.

    1993-01-01

    Conidia of the plant pathogenic fungus Botrytis cinerea adhered to tomato cuticle and to certain other substrata immediately upon hydration. This immediate adhesion occurred with both living and nonliving conidia. Adhesion was not consistently influenced by several lectins, sugars, or salts or by protease treatment, but it was strongly inhibited by ionic or nonionic detergents. With glass and oxidized polyethylene, substrata whose surface hydrophobicities could be conveniently varied, there was a direct relationship between water contact angle and percent adhesion. Immediate adhesion did not involve specific conidial attachment structures, although the surfaces of attached conidia were altered by contact with a substratum. Freshly harvested conidia were very hydrophobic, with more than 97% partitioning into the organic layer when subjected to a phase distribution test. Percent adhesion of germinated conidia was larger than that of nongerminated conidia. Evidence suggests that immediate adhesion of conidia of B. cinerea depends, at least in part, on hydrophobic interactions between the conidia and substratum. Images PMID:16348954

  14. Aquatic hyphomycetes as endophytes of riparian plant roots.

    PubMed

    Sati, S C; Belwal, M

    2005-01-01

    Eighteen species of aquatic hyphomycetes were recorded as root endophytes in roots of living plants including grasses and pteridophytes from wet fields near ravine areas. Alatospora acuminata, A. pulchella, Acaulopage tetraceros, Anguillospora crassa, Campylospora chaetocladia, Lemonniera cornuta, L. pseudofloscula, L. terrestris, Pestalotiopsis submersus and Tetrachaetum elegans were found for the first time as root endophytes. A. longissima, Campylospora purvula, Clavariopsis aquatica, Cylindrocarpon aquaticum, Heliscus lugdunensis, Lunulospora curvula, Tetracladium marchalianum and T. setigerum, which were known previously as root endophytes, are reported here on new hosts. Maximum occurrence was found in November and December. PMID:16389955

  15. Ergosterol-to-Biomass Conversion Factors for Aquatic Hyphomycetes

    PubMed Central

    Gessner, Mark O.; Chauvet, Eric

    1993-01-01

    Fourteen strains of aquatic hyphomycete species that are common on decaying leaves in running waters were grown in liquid culture and analyzed for total ergosterol contents. Media included an aqueous extract from senescent alder leaves, a malt extract broth, and a glucose-mineral salt solution. Concentrations of ergosterol in fungal mycelium ranged from 2.3 to 11.5 mg/g of dry mass. The overall average was 5.5 mg/g. Differences among both species and growth media were highly significant but followed no systematic pattern. Stationary-phase mycelium had ergosterol contents 10 to 12% lower or higher than mycelium harvested during the growth phase, but these differences were only significant for one of four species examined. Availability of plant sterols in the growth medium had no clear effect on ergosterol concentrations in two species tested. To convert ergosterol contents determined in field samples to biomass values of aquatic hyphomycetes, a general multiplicative factor of 182 is proposed. More accurate estimates would be obtained with species-specific factors. Using these in combination with estimates of the proportion of the dominant species in a naturally established community on leaves resulted in biomass estimates that were typically 20% lower than those obtained with the general conversion factor. Improvements of estimates with species-specific factors may be limited, however, by intraspecific variability in fungal ergosterol content. PMID:16348874

  16. Electron Microscopy of Botrytis cinerea Conidia

    PubMed Central

    Buckley, Patricia M.; Sjaholm, Virginia E.; Sommer, N. F.

    1966-01-01

    Buckley, Patricia M. (University of California, Davis), Virginia E. Sjaholm, and N. F. Sommer. Electron microscopy of Botrytis cinerea conidia. J. Bacteriol. 91:2037–2044. 1966.—Sections of germinating and nongerminating Botrytis cinerea conidia were examined with an electron microscope. Uranyl acetate or lead citrate provided contrast between membranes and cytoplasm. Membrane-bounded, dense inclusions previously unreported in dormant spores were termed “storage bodies.” Whorled structures, spherules, granules, and membrane loops were seen within these inclusions. The various forms assumed by the enclosed materials closely resemble phospholipid inclusions described for other cells. It is suggested that the inclusions provide material for the assembly of membranous organelles during germination. Utilization of the stored material apparently results in extensive vacuolization in advanced germinants. Images PMID:5949251

  17. New and rare lignicolous hyphomycetes from Zhejiang Province, China* §

    PubMed Central

    Wongsawas, Mongkol; Wang, Hong-kai; Hyde, Kevin D.; Lin, Fu-cheng

    2008-01-01

    Sporidesmiopsis zhejiangensis sp. nov. and Spadicoides americana were found on submerged wood from streams in Zhejiang Province, China. Sporidesmiopsis zhejiangensis is characterized by obclavate to fusiform, 5-6-distoseptate, versicolorous, verruculose conidia with an apical mucilaginous sheath. Spadicoides americana is a new record to China. These taxa are described and illustrated, and morphological differences between these species and their similar species were summarized. PMID:18837107

  18. Selective medium for isolation of Fusarium species and dematiaceous hyphomycetes from cereals.

    PubMed Central

    Andrews, S; Pitt, J I

    1986-01-01

    A selective medium containing 2 micrograms of dichloran per ml, 200 micrograms of chloramphenicol per ml, and 1.5% bacteriological peptone was developed for the isolation of Fusarium species and dematiaceous hyphomycetes from cereals. The medium, designated DCPA, was shown to select against species of Aspergillus, Penicillium, Cladosporium, and mucoraceous fungi. DCPA was evaluated for use as an enumeration medium and compared satisfactorily with dichloran-rose bengal-chloramphenicol agar when both media were tested with a range of cereal samples. Fusarium species and dematiaceous hyphomycetes produced well-formed colonies with good conidial production on DCPA, permitting rapid identification of such isolates on this medium. PMID:3729399

  19. Selective medium for isolation of Fusarium species and dematiaceous hyphomycetes from cereals.

    PubMed

    Andrews, S; Pitt, J I

    1986-06-01

    A selective medium containing 2 micrograms of dichloran per ml, 200 micrograms of chloramphenicol per ml, and 1.5% bacteriological peptone was developed for the isolation of Fusarium species and dematiaceous hyphomycetes from cereals. The medium, designated DCPA, was shown to select against species of Aspergillus, Penicillium, Cladosporium, and mucoraceous fungi. DCPA was evaluated for use as an enumeration medium and compared satisfactorily with dichloran-rose bengal-chloramphenicol agar when both media were tested with a range of cereal samples. Fusarium species and dematiaceous hyphomycetes produced well-formed colonies with good conidial production on DCPA, permitting rapid identification of such isolates on this medium. PMID:3729399

  20. Splash dispersal of Phyllosticta citricarpa conidia from infected citrus fruit

    PubMed Central

    Perryman, S. A. M.; Clark, S. J.; West, J. S.

    2014-01-01

    Rain-splash dispersal of Phyllosticta citricarpa (syn. Guignardia citricarpa) conidia (pycnidiospores) from infected oranges was studied in still air and combined with wind. High power microscopy demonstrated the presence of conidia in splash droplets from diseased oranges, which exuded conidia for over one hour during repeated wetting. The largest (5 mm) incident drops produced the highest splashes (up to 41.0 cm). A linear-by-quadratic surface model predicted highest splashes to be 41.91 cm at a horizontal distance of 25.97 cm from the target orange. Large splash droplets contained most conidia (4–5.5 mm splashes averaged 308 conidia), but were splashed <30 cm horizontal distance. Most (80–90%) splashes were <1 mm diameter but carried only 0–4 conidia per droplet. In multiple splash experiments, splashes combined to reach higher maxima (up to 61.7 cm; linear-by-quadratic surface model prediction, 62.1 cm) than in the single splash experiments. In combination with wind, higher wind speeds carried an increasing proportion of splashes downwind travelling horizontally at least 8 m at the highest wind speed tested (7 m/s), due to a small proportion of droplets (<1 mm) being aerosolised. These experiments suggest that P. citricarpa conidia can be dispersed from infected oranges by splashes of water in rainfall events. PMID:25298272

  1. Novel delivery of the fungi Paecilomyces formosoroseus (Deuteromycotina: Hyphomycetes) for managing the Asian citrus psyllid (Psyllidae: Hemiptera)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A method was developed to increase efficacy and reduce grower costs when using the biological control fungal agent Paecilomyces fumosoroseus blastospores (Deuteromycotina: Hyphomycetes) to infect adult Asian citrus psyllids, Diaphorina citri (Psyllidae: Hemiptera). We analyzed the efficacy of this A...

  2. Novel delivery of the fungi Paecilomyces formosoroseus (Deuteromycotina: Hyphomycetes) for managing the Asian citrus psyllid (Psyllidae: Hemiptera)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A method was developed to increase efficacy and reduce grower costs when using the biological control fungal agent Paecilomyces fumosoroseus blastospores (Deuteromycotina: Hyphomycetes) to infect adult Asian citrus psyllids, Diaphorina citri (Psyllidae: Hemiptera). We analyzed the efficacy of this ‘...

  3. Collection of highly germinative pseudochain conidia of Oidium neolycopersici from conidiophores by electrostatic attraction.

    PubMed

    Nonomura, Teruo; Matsuda, Yoshinori; Xu, Ling; Kakutani, Koji; Takikawa, Yoshihiro; Toyoda, Hideyoshi

    2009-03-01

    A population of simultaneously germinating conidia is an ideal inoculum of the powdery mildew pathogen, Oidium neolycopersici. In conditions of no or low wind velocity, O. neolycopersici successively stacks mature conidia on conidiophores in a chain formation (pseudochain), without releasing the precedent mature conidia. These pseudochain conidia represent a perfect inoculum, in which all conidia used for inoculation germinate simultaneously. However, we found that conidia must be collected before they fall to the leaf surface, because the germination rate was lower among conidia deposited on the leaf surface. We used an electrostatic spore collector to collect the pseudochain conidia, and their high germination rate was not affected by this treatment. The spore collector consisted of an electrified insulator probe, which created an electrostatic field around its pointed tip, and attracted conidia within its electric field. The attractive force created by the probe tip was directly proportional to voltage, and was inversely proportional to the distance between the tip and a target colony on a leaf. Pseudochain conidia were successfully collected by bringing the electrified probe tip close to target colonies on leaves. In this way, conidia were collected from colonies at 3-d intervals. This effectively collected all conidia from conidiophores before they dropped to the leaf surface. A high germination rate was observed among conidia attracted to the probe tip (95.5+/-0.6%). Conidia were easily suspended in water with added surfactant, and retained their germination ability. These conidia were infective and produced conidia in pseudochains on conidiophores after inoculation. The electrostatic spore collection method can be used to collect conidia as they form on conidiophores, thus obtaining an inoculum population in which all of the conidia germinate simultaneously. PMID:19070662

  4. Hyalodendrosides A and B, antifungal triterpenoid glycosides from a lignicolous hyphomycete, Hyalodendron species.

    PubMed

    Bills, G; Dombrowski, A; Morris, S A; Hensens, O; Liesch, J M; Zink, D L; Onishi, J; Meinz, M S; Rosenbach, M; Thompson, J R; Schwartz, R E

    2000-01-01

    Two antifungal triterpenoid glycosides, hyalodendrosides A and B (1 and 2), were isolated from a solid matrix fermentation of a lignicolous hyphomycete, Hyalodendron sp. Their structures were determined based upon extensive examination of spectral parameters, particularly NMR and MS data. Both compounds have beta-linked glucose moieties. Compounds 1 and 2 show weak to moderate antifungal activity against some clinically relevant fungi. PMID:10650085

  5. Aquatic Hyphomycete Species Are Screened by the Hyporheic Zone of Woodland Streams

    PubMed Central

    Chauvet, Eric; Mermillod-Blondin, Florian; Assemat, Fiona; Elger, Arnaud

    2014-01-01

    Aquatic hyphomycetes strongly contribute to organic matter dynamics in streams, but their abilities to colonize leaf litter buried in streambed sediments remain unexplored. Here, we conducted field and laboratory experiments (slow-filtration columns and stream-simulating microcosms) to test the following hypotheses: (i) that the hyporheic habitat acting as a physical sieve for spores filters out unsuccessful strategists from a potential species pool, (ii) that decreased pore size in sediments reduces species dispersal efficiency in the interstitial water, and (iii) that the physicochemical conditions prevailing in the hyporheic habitat will influence fungal community structure. Our field study showed that spore abundance and species diversity were consistently reduced in the interstitial water compared with surface water within three differing streams. Significant differences occurred among aquatic hyphomycetes, with dispersal efficiency of filiform-spore species being much higher than those with compact or branched/tetraradiate spores. This pattern was remarkably consistent with those found in laboratory experiments that tested the influence of sediment pore size on spore dispersal in microcosms. Furthermore, leaves inoculated in a stream and incubated in slow-filtration columns exhibited a fungal assemblage dominated by only two species, while five species were codominant on leaves from the stream-simulating microcosms. Results of this study highlight that the hyporheic zone exerts two types of selection pressure on the aquatic hyphomycete community, a physiological stress and a physical screening of the benthic spore pool, both leading to drastic changes in the structure of fungal community. PMID:24441154

  6. Capillary electrophoresis of conidia from cultivated microscopic filamentous fungi.

    PubMed

    Horká, Marie; Růzicka, Filip; Kubesová, Anna; Holá, Veronika; Slais, Karel

    2009-05-15

    In immunocompromised people fungal agents are able to cause serious infections with high mortality rate. An early diagnosis can increase the chances of survival of the affected patients. Simultaneously, the fungi produce toxins and they are frequent cause of allergy. Currently, various methods are used for detection and identification of these pathogens. They use microscopic examination and growth characteristic of the fungi. New methods are based on the analysis of structural elements of the target microorganisms such as proteins, polysaccharides, glycoproteins, nucleic acids, etc. for the construction of antibodies, probes, and primers for detection. The above-mentioned methods are time-consuming and elaborate. Here hydrophobic conidia from the cultures of different strains of the filamentous fungi were focused and separated by capillary zone electrophoresis and capillary isoelectric focusing. The detection was optimized by dynamic modifying of conidia by the nonionogenic tenside on the basis of pyrenebutanoate. Down to 10 labeled conidia of the fungal strains were fluorometrically detected, and isoelectric points of conidia were determined. The observed isoelectric points were compared with those obtained from the separation of the cultured clinical samples, and they were found to be not host-specific. PMID:19385663

  7. Optimization of Solid-State Fermentation for Improved Conidia Production of Beauveria bassiana as a Mycoinsecticide

    PubMed Central

    Pham, Tuan Anh; Kim, Jeong Jun

    2010-01-01

    The production of conidia of entomopathogenic Beauveria bassiana by solid-state fermentation was studied for the development of a biocontrol agent against aphid Myzus persicae. The optimal conditions for conidia production on polished white rice were 40% moisture content, 25℃ culture temperature, 2-day-old seeding culture grown in 3% corn meal, 2% rice bran, 2% corn steep powder medium, initial conidia concentration of 107 conidia/g in the wet rice, 10% inoculum size, and use of a polyethylene bag as a container. The polyethylene bag containing inoculated rice was hand-shaken every 12 hr during fermentation. Using optimal conditions, the maximum conidia production obtained was 4.05 g conidia/100 g dry rice after 14 days of cultivation, a rate 2.83 times higher than conidia yield of pre-optimization. PMID:23956642

  8. Optimization of Solid-State Fermentation for Improved Conidia Production of Beauveria bassiana as a Mycoinsecticide.

    PubMed

    Pham, Tuan Anh; Kim, Jeong Jun; Kim, Keun

    2010-06-01

    The production of conidia of entomopathogenic Beauveria bassiana by solid-state fermentation was studied for the development of a biocontrol agent against aphid Myzus persicae. The optimal conditions for conidia production on polished white rice were 40% moisture content, 25℃ culture temperature, 2-day-old seeding culture grown in 3% corn meal, 2% rice bran, 2% corn steep powder medium, initial conidia concentration of 10(7) conidia/g in the wet rice, 10% inoculum size, and use of a polyethylene bag as a container. The polyethylene bag containing inoculated rice was hand-shaken every 12 hr during fermentation. Using optimal conditions, the maximum conidia production obtained was 4.05 g conidia/100 g dry rice after 14 days of cultivation, a rate 2.83 times higher than conidia yield of pre-optimization. PMID:23956642

  9. Heterogeneity in liquid shaken cultures of Aspergillus niger inoculated with melanised conidia or conidia of pigmentation mutants

    PubMed Central

    van Veluw, G.J.; Teertstra, W.R.; de Bekker, C.; Vinck, A.; van Beek, N.; Muller, W.H.; Arentshorst, M.; van der Mei, H.C.; Ram, A.F.J.; Dijksterhuis, J.; Wösten, H.A.B.

    2013-01-01

    Black pigmented conidia of Aspergillus niger give rise to micro-colonies when incubated in liquid shaken medium. These micro-colonies are heterogeneous with respect to gene expression and size. We here studied the biophysical properties of the conidia of a control strain and of strains in which the fwnA, olvA or brnA gene is inactivated. These strains form fawn-, olive-, and brown-coloured conidia, respectively. The ΔolvA strain produced larger conidia (3.8 μm) when compared to the other strains (3.2–3.3 μm). Moreover, the conidia of the ΔolvA strain were highly hydrophilic, whereas those of the other strains were hydrophobic. The zeta potential of the ΔolvA conidia in medium was also more negative when compared to the control strain. This was accompanied by the near absence of a rodlet layer of hydrophobins. Using the Complex Object Parametric Analyzer and Sorter it was shown that the ratio of individual hyphae and micro-colonies in liquid shaken cultures of the deletion strains was lower when compared to the control strain. The average size of the micro-colonies of the control strain was also smaller (628 μm) than that of the deletion strains (790–858 μm). The size distribution of the micro-colonies of the ΔfwnA strain was normally distributed, while that of the other strains could be explained by assuming a population of small and a population of large micro-colonies. In the last set of experiments it was shown that relative expression levels of gpdA, and AmyR and XlnR regulated genes correlate in individual hyphae at the periphery of micro-colonies. This indicates the existence of transcriptionally and translationally highly active and lowly active hyphae as was previously shown in macro-colonies. However, the existence of distinct populations of hyphae with high and low transcriptional and translational activity seems to be less robust when compared to macro-colonies grown on solid medium. PMID:23449476

  10. Preparation of fungal conidia impacts their susceptibility to inactivation by ethanol vapours.

    PubMed

    Dao, Thien; Dantigny, Philippe

    2009-11-15

    A common protocol employed for the preparation of conidia employs flooding a fungal colony grown on semi-solid media under optimum conditions with an aqueous solution. In contrast, conidia produced in a natural environment are usually not hydrated when disseminated in air and can be produced under water stress. In order to simulate the latter conditions, cultures were grown at different water activities and conidia were dry-harvested on the lid by turning the dishes upside-down then gently tapping the bottom of the box. This study aimed at assessing the effect of the preparation of fungal conidia on their inactivation by ethanol vapours. Firstly ethanol vapours (either 0.30 or 0.45 kPa) were applied to conidia obtained from the standardised protocol and to dry-harvested conidia for some species of Penicillium. While all dry-harvested conidia remained viable after 24 h of treatment, about 1.0, 3.5 and 2.5 log(10) reductions were observed for hydrated conidia of Penicillium chrysogenum, Penicillium digitatum and Penicillium italicum respectively. Secondly ethanol vapours (0.67 kPa) were applied to dry-harvested conidia obtained from cultures grown at 0.99 a(w) and at reduced water activities. For all species, the susceptibility to ethanol vapours of conidia obtained at 0.99 a(w) was significantly greater than that of conidia obtained at reduced water activities. Conidia produced in a natural environment under non-optimal conditions would be much more resistant to ethanol vapours than those produced in the laboratory. This phenomenon may be due to a reduced intracellular water activity of dry-harvested conidia. PMID:19762103

  11. Effects of cadmium on aquatic hyphomycetes. [Alatospora acuminata; Clavariopsis aquatica; Flagellospora curvula; Heliscus lugdunesis; Tetracladium marchalianum

    SciTech Connect

    Abel, T.H.; Baerlocher, F.

    1984-08-01

    Two kinds of experiments, sporulation and growth experiments, were carried out to demonstrate the effect of cadmium on aquatic hyphomycetes. Oak (Quercus petraea L.) leaves were exposed in a hard-water stream (Luessel, Swiss Jura) and a soft-water stream (Ibach, Black Forest) for 2 months. In the laboratory, fungal sporulation on the leaves in stream water enriched with cadmium (as CdCl/sub 2/) was studied. A measureable effect was found when the cadmium concentration exceeded 0.1 ppm (0.1 mg/liter). Concentrations higher than 100 ppm inhibited conidium production completely. This toxic effect of cadmium was species dependent and much higher in soft water (water with low concentrations of calcium and magnesium) than in hard water. Growth experiments with Alatospora acuminata Ingold, Clavaropsis aquatica De Wildeman, Flagellospora curvula Ingold, Heliscus lugdunensis Saccardo and Therry, and Tetracladium marchalianum De Wildeman showed the same pattern of cadmium sensitivity as that seen in the sporulation experiments. Mycelial growth was less sensitive to cadmium than was fungal sporulation. High concentrations of competing cations (e.g., calcium and zinc) or potential ligands could reduce cadmium toxicity. Calcium content seems to be the most important factor responsible for the different sensitivity of aquatic hyphomycetes in hard and soft water.

  12. Production of conidia of Penicillium camemberti in liquid medium through microcycles of conidiation.

    PubMed

    Boualem, Khadidja; Gervais, Patrick; Cavin, Jean-François; Waché, Yves

    2014-11-01

    Microcycle conidiation is a survival mechanism of fungi encountering unfavorable conditions. In this phenomenon, asexual spores germinate secondary spores directly without formation of mycelium. As Penicillium camemberti conidia have the ability to produce conidiophores after germination in liquid culture induced by a thermal stress (18 and 30 °C), our work has aimed at producing conidia through this mean. Incubation at 18 and 30 °C increased the swelling of conidia and their proportion thereby producing conidiophores. Our results showed that the microcycle of conidiation can produce 5 × 10(8) conidia ml(-1) after 7 days at 18 °C of culture. The activity of these conidia was checked through culture on a solid medium. Conidia produced by microcycle conidiation formed a normal mycelium on the surface of solid media and 25 % could still germinate after 5 months of storage. PMID:24975730

  13. Trichothecene mycotoxins in aerosolized conidia of Stachybotrys atra.

    PubMed Central

    Sorenson, W G; Frazer, D G; Jarvis, B B; Simpson, J; Robinson, V A

    1987-01-01

    Stachybotrys atra is the etiologic agent of stachybotryotoxicosis, and this fungus and its trichothecene mycotoxins were recently implicated in an outbreak of unexplained illness in homes. S. atra was grown on sterile rice, autoclaved, dried, and then aerosolized by acoustic vibration. The distribution of particles (mass and number) was monitored on an aerodynamic particle sizer interfaced with a computer. Dust was collected on preweighed glass-fiber filters and extracted with 90% aqueous methanol. Extracts were tested for the ability to inhibit protein synthesis in rat alveolar macrophages, the ability to inhibit the proliferation of mouse thymocytes, and the presence of specific trichothecene mycotoxins. Virtually all of the particles were less than 15 micron in aerodynamic diameter, and the mass median diameter was 5 micron. Thus, most of the particles were respirable. Microscopic analysis of the generated dust revealed that ca. 85% of the dust particles were conidia of S. atra, another 6% were hyphal fragments, and the remainder of the particles were unidentifiable. Thus, greater than 90% of the particles were of fungal origin. The extracts strongly inhibited protein synthesis and thymocyte proliferation. Purified satratoxin H was also highly toxic in the same systems. Each of the individual filters contained satratoxin H (average, 9.5 ng/mg of dust). Satratoxin G and trichoverrols A and B were found in lesser amounts in some, but not all, of the filters. The limit of analysis is ca. 50 ng. These results establish that the conidia of S. atra contain trichothecene mycotoxins. In view of the potent toxicity of the trichothecenes, the inhalation of aerosols containing high concentrations of these conidia could be a potential hazard to health. PMID:3496850

  14. Production of conidia of Beauveria bassiana in solid-state culture: current status and future perspectives.

    PubMed

    Lopez-Perez, M; Rodriguez-Gomez, D; Loera, O

    2015-01-01

    Beauveria bassiana is an important entomopathogenic fungus widely commercialized in the world. Recent progress and achievements on conidia production have focused on a yield goal of 10(9) to 10(10) conidia per gram of dry substrate. Due to cost-competitive perspectives, these yields should be associated with better production rates or productivities. This study presents a review of relevant studies of B. bassiana conidia production on solid-state cultures and the parameters that should be taken into account to maintain constant quality in the product to be commercialized. Conditions for maximizing production and infectivity of B. bassiana conidia are also analysed. PMID:24494702

  15. Expression and identification of a laminin-binding protein in Aspergillus fumigatus conidia.

    PubMed Central

    Tronchin, G; Esnault, K; Renier, G; Filmon, R; Chabasse, D; Bouchara, J P

    1997-01-01

    Adhesion of Aspergillus fumigatus, the causative agent of human aspergillosis, to the extracellular matrix protein laminin has been previously demonstrated. This study investigated the expression of laminin receptors during swelling of conidia, a step leading to germination and subsequent colonization of tissues. Scanning electron microscopy showed that the laminin binding sites were distributed over the external rodlet layer of resting conidia. During swelling, the characteristic rodlet layer progressively disintegrated and conidia surrounded by a smooth cell wall layer appeared. Flow cytometry using fluorescein isothiocyanate-conjugated laminin demonstrated that expression of laminin receptors at the surface of conidia was swelling dependent. Resting conidia expressed high levels of laminin receptors on their surface. A gradual decrease of laminin binding was then observed as swelling occurred, reaching a minimum for 4-h-swollen conidia. This correlated with a loss of adherence of swollen conidia to laminin immobilized on microtiter plates. Trypsin pretreatment of conidia reduced laminin binding. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and ligand blotting with laminin identified in a cell wall extract a major 72-kDa cell wall glycoprotein which binds laminin. Thus, one of the initial events in the host colonization may be the recognition of basement membrane laminin by this 72-kDa cell wall surface component. PMID:8975886

  16. Microencapsuling aerial conidia of Trichoderma harzianum through spray drying at elevated temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Trichoderma conidia are mostly produced by solid fermentation systems. Inoculum is produced by liquid culturing, and then transferred to solid substrate for aerial conidial production. Aerial conidia of T. harzianum are hydrophilic in nature, and it is difficult to separate them from the solid subst...

  17. Phagocytosis of Aspergillus fumigatus conidia by primary nasal epithelial cells in vitro

    PubMed Central

    Botterel, Françoise; Gross, Karine; Ibrahim-Granet, Oumaïma; Khoufache, Khaled; Escabasse, Virginie; Coste, André; Cordonnier, Catherine; Escudier, Estelle; Bretagne, Stéphane

    2008-01-01

    Background Invasive aspergillosis, which is mainly caused by the fungus Aspergillus fumigatus, is an increasing problem in immunocompromised patients. Infection occurs by inhalation of airborne conidia, which are first encountered by airway epithelial cells. Internalization of these conidia into the epithelial cells could serve as a portal of entry for this pathogenic fungus. Results We used an in vitro model of primary cultures of human nasal epithelial cells (HNEC) at an air-liquid interface. A. fumigatus conidia were compared to Penicillium chrysogenum conidia, a mould that is rarely responsible for invasive disease. Confocal microscopy, transmission electron microscopy, and anti-LAMP1 antibody labeling studies showed that conidia of both species were phagocytosed and trafficked into a late endosomal-lysosomal compartment as early as 4 h post-infection. In double immunolabeling experiments, the mean percentage of A. fumigatus conidia undergoing phagocytosis 4 h post-infection was 21.8 ± 4.5%. Using combined staining with a fluorescence brightener and propidium iodide, the mean rate of phagocytosis was 18.7 ± 9.3% and the killing rate 16.7 ± 7.5% for A. fumigatus after 8 h. The phagocytosis rate did not differ between the two fungal species for a given primary culture. No germination of the conidia was observed until 20 h of observation. Conclusion HNEC can phagocytose fungal conidia but killing of phagocytosed conidia is low, although the spores do not germinate. This phagocytosis does not seem to be specific to A. fumigatus. Other immune cells or mechanisms are required to kill A. fumigatus conidia and to avoid further invasion. PMID:18564423

  18. Hypocrea/Trichoderma: species with conidiophore elongations and green conidia.

    PubMed

    Chaverri, Priscila; Castlebury, Lisa A; Overton, Barrie E; Samuels, Gary J

    2003-01-01

    Species of Trichoderma and Hypocrea that have green conidia and sterile or fertile elongations of their conidiophores are described or redescribed and their phylogenetic position explored. The described species include T. crassum, T. fasciculatum, T. fertile, T. hamatum, T. longipile, T. oblongisporum, T. pubescens, T. spirale, T. strictipile, T. strigosum, T. stromaticum, T. tomentosum, Hypocrea aureoviridis f. macrospora, H. ceramica. and H. semiorbis. Trichoderma fasciculatum originally was described from cultures from ascospores of an unidentified Hypocrea specimen; it is considered to be a synonym of T. strictipile. The remaining species of Trichoderma considered here have not been linked to teleomorphs, and the Trichoderma anamorphs of H. aureoviridis f. macrospora and H. semiorbis have not been named. Five new species of Hypocrea are described, viz. H. cremea, H. cuneispora, H. estonica, H. strictipilosa and H. surrotunda. The phylogenetic relationships of these species were inferred based on partial RPB2 and EF-1α DNA sequence data and phenotypic characteristics, including teleomorph, anamorph, colony and growth rates. Trichoderma crassum was found to be a sister species to T. virens, based on molecular sequences and phenotypic data. Hypocrea surrotunda and H. cremea, H. cuneispora and T. longipile, T. fertile and T. oblongisporum, T. tomentosum and H. atrogelatinosa, and T. hamatum and T. pubescens, respectively, were found to be closely related phylogenetically, based on RPB2 and EF-1α gene genealogies. Anamorph and teleomorph phenotype, including conidiophore elongations, phialide morphology, conidial morphology, stroma anatomy and ascospore morphology are not useful predictors of relationships. Despite the shared phenotypic characters of these Trichoderma and Hypocrea species, they are distributed between two major clades of Trichoderma/Hypocrea. Redescriptions and a key to species of Hypocrea/Trichoderma with green conidia and conidiophore

  19. Inactivation of conidia of Paecilomyces fumosoroseus by near-ultraviolet (UVB and UVA) and visible radiation.

    PubMed

    Fargues, J; Rougier, M; Goujet, R; Smits, N; Coustere, C; Itier, B

    1997-01-01

    The detrimental effects of solar radiation, especially the ultraviolet waveband, on quiescent conidia of Paecilomyces fumosoroseus were investigated. Conidia were irradiated by a high-intensity source, which emitted a continuous spectrum from 270 to 1100 nm and which was equipped with long-pass filters to block short wavelengths below 280, 295, 320, or 400 nm. After irradiation, conidia were tested for germinability, survival, and infectivity toward Spodoptera frugiperda larvae. It was demonstrated that the detrimental effects of light depended on irradiance in the shortest wavelengths. The UVB (280-320 and 295-320 nm) appeared to be the most detrimental part of natural radiation, although UVA (320-400 nm) was also harmful. Visible and near infrared radiations were less harmful than UV. Our results demonstrate that the irradiance of the UVB waveband should be considered as the pertinent factor for the detrimental effects of sunlight on the persistence of conidia of entomopathogenic fungi in insolated environments. PMID:9028931

  20. A staining method for assessing the viability of Esteya vermicola conidia.

    PubMed

    Wang, Yunbo; Thang, NguyenTrong; Li, Zheng; Zhang, Yongan; Li, Jingjie; Xue, Jianjie; Gu, Lijuan; Hong, VuThuy; Mira, Lee; Sung, Changkeun

    2014-07-01

    The viability of conidia of Esteya vermicola, a potentially important biocontrol agent against the pinewood nematode Bursaphelenchus xylophilus, is usually determined by cultivation for 18-48 h in culture medium. As an alternative to this labor-intensive method, we have developed a rapid, simple, and low-cost staining method for assessing E vermicola conidia survival rates. A mixture of neutral red and methylene blue was found to be the most optimal among several stains that also included safranin O and Janus green B. This mixture stained nonviable conidia blue, in contrast to viable conidia, which were stained red in the cytoplasm and blue in the cell wall. This method may be particularly useful for traditional research laboratories, as it provides rapid results using common, relatively inexpensive laboratory equipment. PMID:24585076

  1. Germination of fungal conidia after exposure to low concentration ozone atmospheres.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The germinability of conidia of Alternaria alternata, Aspergillus flavus, Aspergillus niger, Penicillium digitatum, Penicillium expansum, or Penicillium italicum was determined periodically during exposure for approximately 100 days to a humid atmosphere of air alone or air containing 150 ppb ozone ...

  2. THE POWER OF THE SMALL: THE EXAMPLE OF Paracoccidioides brasiliensis CONIDIA

    PubMed Central

    RESTREPO, Angela; CANO, Luz Elena; GONZALEZ, Ángel

    2015-01-01

    SUMMARY Research on Paracoccidioides brasiliensis has centered in the yeast cell probably because of the lack of distinctive features in the mycelium. In 1942 and for the first time, lateral conidia were noticed in the fungus' hyphae. Later on, Brazilian, Venezuelan and Argentinean researchers described "aleurias" when the fungus was grown in natural substrates. In 1970 authors became interested in the conidia and were able to obtain them in large numbers and treat them as individual units. Their shape and size were defined and the presence of all the elements of a competent eukaryotic cell were demonstrated. Conidia exhibited thermal dimorphism and, additionally, when given intranasally to BALB/c male mice, they converted into yeasts in the lungs and produce progressive pulmonary lesions with further dissemination to other organs. Studies on the phagocyte-conidia interaction were revealing and showed that these versatile structures allow a better understanding of the host- P. brasiliensis interactions. PMID:26465363

  3. Comparison of methodologies for conidia production by Alternaria alternata from citrus

    PubMed Central

    Carvalho, Daniel D. C.; Alves, Eduardo; Batista, Tereza R. S.; Camargos, Renato B.; Lopes, Eloísa A. G. L.

    2008-01-01

    Conidia production is a problem in the study of Alternaria alternata from citrus. Thus, this study aimed to compare existing methodologies for conidial production of A. alternata isolated from Ponkan tangerine (2 isolates), Cravo lemon (1 isolate), Pêra orange (2 isolates) and Murcott tangor (1 isolate). The methodologies used were conidia production with 12 and 24 hours under white fluorescent light, evaluation with 24 and 48 hours after applying fungal mycelium stress technique, cold stress followed by injury of mycelium and evaluation with 24 hours, using healthy vegetable tissue and the use of black fluorescent near ultraviolet (NUV) lamp. Satisfactory result was obtained with A. alternata isolate from Murcott tangor, with the production of 2.8 × 105 conidia mL-1, when fungal mycelium was stressed (Petri dish with 66.66% of fungi growth) and subsequently 24 h of growth. The use of white light (24 h) and black fluorescent NUV lamp also induced expressive conidia production by one isolate of Ponkan tangerine, which produced 17.2 × 105 and 10.1 × 105conidia mL-1 and another of Murcott tangor, which produced 13.9 × 105 and 10.1 × 105 conidia mL-1, respectively. The remaining methodologies analyzed in this study were not able to induce conidia production in satisfactory quantity. The use of both mycelium stress technique and white light (24 h) and black fluorescent NUV lamp allowed the production of enough quantities of conidia to be used in vitro (detection of fungitoxic substances) and in vivo (pathogenicity test) assays, respectively. PMID:24031309

  4. Cadmium-induced formation of sulphide and cadmium sulphide particles in the aquatic hyphomycete Heliscus lugdunensis.

    PubMed

    Dobritzsch, Dirk; Ganz, Petra; Rother, Michael; Ehrman, James; Baumbach, Renate; Miersch, Jürgen

    2015-01-01

    Freshwater fungi which can survive under metal exposure receive increasing scientific attention. Enhanced synthesis of sulphide and glutathione but no phytochelatin synthesis in response to cadmium (up to 80 μM Cd(2+) in the medium) was measured in the aquatic hyphomycete Heliscus lugdunensis. Up to 25 μmol g(-1) dry mass the fungus formed sulphide in an exponentially Cd(2+)-concentration-dependent manner. Using light microscopy, precipitates were observed outside of the hyphae which could be determined as amorphous particles by X-ray diffraction (XRD). Energy dispersive X-ray spectroscopy (EDS) analysis indicated that these particles were mainly composed of Cd and S with an atomic ratio of 1:1, but some elements of the culture medium such as P and Cl were also present. Fungal cells exposed to Cd(2+) accumulated 12-28 μmol metal g(-1) dry mass over a period of 7-28 days. The results may indicate that sulphide could sequester excess Cd(2+) under oxygen deprived conditions and thereby reduce its toxicity via an additional avoidance mechanism of this fungus. PMID:26004898

  5. Bioactivity of Root Endophytic Freshwater Hyphomycetes Anguillospora longissima (Sacc. & Syd.) Ingold

    PubMed Central

    Sati, S. C.; Singh, Lokendra

    2014-01-01

    Anguillospora longissima, isolated from root as endophytic freshwater hyphomycetes, was evaluated for its bioactivity (antibacterial potential) against five bacterial strains, namely, Gram-positive (Bacillus subtilis MTCC 121) and Gram-negative (Agrobacterium tumefaciens MTCC 609, Escherichia coli MTCC 40, Erwinia chrysanthemum, and Xanthomonas pseudomonas). Antimicrobial activity was assessed by measuring the zone of inhibition with preliminary and secondary antimicrobial assays. The applied fungus was found significant for all tested bacterial strains as showen by their zone of inhibition. In preliminary antimicrobial assay, maximum zone of inhibition was recorded against Gram-negative human pathogenic bacterial strain Escherichia coli (23 mm) followed by Erwinia chrysanthemi (22 mm), Agrobacterium tumefaciens (21 mm), and Xanthomonas phaseoli (21 mm), while minimum zone of inhibition was observed against Bacillus subtilis (20 mm). In secondary antimicrobial assay, the maximum zone of inhibition was recorded against Erwinia chrysanthemi (11 mm) followed by Agrobacterium tumefaciens (10 mm), Xanthomonas phaseoli (10 mm), and Bacillus subtilis (9 mm) and minimum inhibition was found against Escherichia coli (8 mm). PMID:25383378

  6. Response of Aquatic Hyphomycete Communities to Changes in Heavy Metal Exposure

    NASA Astrophysics Data System (ADS)

    Sridhar, K. R.; Bärlocher, Felix; Krauss, Gerd-Joachim; Krauss, Gudrun

    2005-02-01

    Decomposition of Alnus glutinosa (alder) leaves was studied in a severely (site H4) and a moderately (site H8) heavy metal polluted stream in the former copper shale mining district of Mansfeld, Central Germany. Leaves at H8 had reduced fungal diversity and spore production but a high exponential decay rate (k = 0.065). No further mass loss of leaves occurred at H4 after 4-6 weeks, and fungal diversity and spore production were lower than in H8. Decay and sporulation rates gradually increased to values of H8 control leaves in leaves preincubated in H4 and then transferred to H8. These increases correlated with the invasion of transplanted leaves by Tetracladium marchalianum and Tricladium angulatum. In the reverse transplant experiment (H8 to H4), mass loss appeared to stop immediately. Sporulation rates also declined, but remained consistently above levels in H4 control leaves. Leaves precolonized in the laboratory by one of three aquatic hyphomycete species exhibited increased decay rates in both streams. Sporulation rates on these leaves were greater than those of control leaves in H4, but smaller than those of control leaves in H8.

  7. Variations in UV-B tolerance and germination speed of Metarhizium anisopliae conidia produced on insects and artificial substrates.

    PubMed

    Rangel, Drauzio E N; Braga, Gilberto U L; Flint, Stephan D; Anderson, Anne J; Roberts, Donald W

    2004-01-01

    Solar ultraviolet radiation (UV-A and UV-B) is a major factor in failure of programs using the insect pathogenic fungus Metarhizium anisopliae as a biological control agent. Studies were conducted to determine if growth conditions, viz. artificial (agar media or rice grain) or natural (infected insects) substrates for conidial production affect two traits that directly influence performance of conidia after field application: tolerance to UV-B radiation and conidial germination speed. Conidia of two isolates (ARSEF 23 and ARSEF 2575) of M. anisopliae var. anisopliae produced on potato dextrose agar plus yeast extract (PDAY) or on fungus-killed larvae of two insect species, Galleria mellonella and Zophobas morio, were inactivated by exposure to UV-B radiation. Conidia of both isolates when produced on insect cadavers were significantly more sensitive to UV-B radiation than conidia produced on PDAY. Also, conidia from insect cadavers germinated slower than those from PDAY cultures. A comparison of conidia from artificial substrates showed that conidia produced on Czapek's and Emerson's YpSs agar media or rice grains had higher tolerance to UV-B radiation and germinated faster than conidia raised on PDA and PDAY. Accordingly, the growth substrate and nutritional environment in which conidia are produced influences M. anisopliae conidial UV-B tolerance and speed of germination; and manipulation of these variables could be used to obtain conidia with increased tolerance to UV-B radiation and shorter germination times. PMID:15579316

  8. Influence of Additives on the Yield and Pathogenicity of Conidia Produced by Solid State Cultivation of an Isaria javanica Isolate.

    PubMed

    Kim, Jeong Jun; Xie, Ling; Han, Ji Hee; Lee, Sang Yeob

    2014-12-01

    Recently, the Q biotype of tobacco whitefly has been recognized as the most hazardous strain of Bemisia tabaci worldwide, because of its increased resistance to some insecticide groups. As an alternative control agent, we selected an Isaria javanica isolate as a candidate for the development of a mycopesticide against the Q biotype of sweet potato whitefly. To select optimal mass production media for solid-state fermentation, we compared the production yield and virulence of conidia between 2 substrates (barley and brown rice), and we also compared the effects of various additives on conidia production and virulence. Barley was a better substrate for conidia production, producing 3.43 × 10(10) conidia/g, compared with 3.05 × 10(10) conidia/g for brown rice. The addition of 2% CaCO3 + 2% CaSO4 to barley significantly increased conidia production. Addition of yeast extract, casein, or gluten also improved conidia production on barley. Gluten addition (3% and 1.32%) to brown rice improved conidia production by 14 and 6 times, respectively, relative to brown rice without additives. Conidia cultivated on barley produced a mortality rate of 62% in the sweet potato whitefly after 4-day treatment, compared with 53% for conidia cultivated on brown rice. The amendment of solid substrate cultivation with additives changed the virulence of the conidia produced; the median lethal time (LT50) was shorter for conidia produced on barley and brown rice with added yeast extract (1.32% and 3%, respectively), KNO3 (0.6% and 1%), or gluten (1.32% and 3%) compared with conidia produced on substrates without additives. PMID:25606006

  9. Influence of Additives on the Yield and Pathogenicity of Conidia Produced by Solid State Cultivation of an Isaria javanica Isolate

    PubMed Central

    Xie, Ling; Han, Ji Hee; Lee, Sang Yeob

    2014-01-01

    Recently, the Q biotype of tobacco whitefly has been recognized as the most hazardous strain of Bemisia tabaci worldwide, because of its increased resistance to some insecticide groups. As an alternative control agent, we selected an Isaria javanica isolate as a candidate for the development of a mycopesticide against the Q biotype of sweet potato whitefly. To select optimal mass production media for solid-state fermentation, we compared the production yield and virulence of conidia between 2 substrates (barley and brown rice), and we also compared the effects of various additives on conidia production and virulence. Barley was a better substrate for conidia production, producing 3.43 × 1010 conidia/g, compared with 3.05 × 1010 conidia/g for brown rice. The addition of 2% CaCO3 + 2% CaSO4 to barley significantly increased conidia production. Addition of yeast extract, casein, or gluten also improved conidia production on barley. Gluten addition (3% and 1.32%) to brown rice improved conidia production by 14 and 6 times, respectively, relative to brown rice without additives. Conidia cultivated on barley produced a mortality rate of 62% in the sweet potato whitefly after 4-day treatment, compared with 53% for conidia cultivated on brown rice. The amendment of solid substrate cultivation with additives changed the virulence of the conidia produced; the median lethal time (LT50) was shorter for conidia produced on barley and brown rice with added yeast extract (1.32% and 3%, respectively), KNO3 (0.6% and 1%), or gluten (1.32% and 3%) compared with conidia produced on substrates without additives. PMID:25606006

  10. Effects of Metarhizium anisopliae conidia mixed with soil against the eggs of Aedes aegypti.

    PubMed

    Leles, Renan Nunes; D'Alessandro, Walmirton Bezerra; Luz, Christian

    2012-04-01

    The effectiveness of Metarhizium anisopliae IP 46 conidia mixed with soil was tested against Aedes aegypti eggs. Mycelium and new conidia developed first on eggs between 4.8 and 15 days respectively after incubation of fungus-treated soils at 3.3 × 10(3) up to 3.3 × 10(5) conidia/g soil at 25°C and relative humidities close to saturation. After 15-day incubation, 53.3% of the eggs exposed to soil with 3.3 × 10(5) conidia/g showed external development of mycelium and conidia. Fungus-inoculated soils (but not untreated controls) showed some mycelial growth and sporulation apart from the eggs. Some eggs on treated soils hatched; those larvae died and eventually showed fungal development on their bodies. The cumulative relative eclosion of larvae after submersion of treated eggs in water decreased from 52.2% at 3.3 × 10(3) conidia/g to 25.3% at 3.3 × 10(5) conidia/g. These findings clearly showed that A. aegypti eggs can be infected by M. anisopliae when deposited on fungus-contaminated soil. The effectiveness of M. anisopliae against gravid females, larvae, and also eggs of A. aegypti underscored the possible usefulness of this fungus as a mycoinsecticide, whether naturally occurring or artificially applied, in the breeding sites of this mosquito. PMID:21984368

  11. Production of Aerial Conidia of Lecanicillium lecanii 41185 by Solid-State Fermentation for Use as a Mycoinsecticide

    PubMed Central

    Vu, Van Hanh; Hong, Suk Il

    2008-01-01

    The production of aerial conidia of Lecanicillium lecanii 41185, a highly virulent fungus, by solid-state fermentation was studied for use as a biocontrol agent against aphids. Among several agro-industrial solid media, steamed polished rice was found to produce the highest amount of aerial conidia. The optimal conditions for aerial conidia production were determined to be a 28.5% moisture content in the rice, 25℃ culture temperature, rice pH of 6.0, 75% ambient relative humidity, 4-dold seeding culture, 0.6% KNO3, and 12 d of culture time. The conidia yield increased from 5.7 × 109 conidia/g polished rice to 18.2 × 109 conidia/g polished rice following application of these optimized conditions. PMID:23997622

  12. Metabolic activity in dormant conidia of Aspergillus niger and developmental changes during conidial outgrowth.

    PubMed

    Novodvorska, Michaela; Stratford, Malcolm; Blythe, Martin J; Wilson, Raymond; Beniston, Richard G; Archer, David B

    2016-09-01

    The early stages of development of Aspergillus niger conidia during outgrowth were explored by combining genome-wide gene expression analysis (RNAseq), proteomics, Warburg manometry and uptake studies. Resting conidia suspended in water were demonstrated for the first time to be metabolically active as low levels of oxygen uptake and the generation of carbon dioxide were detected, suggesting that low-level respiratory metabolism occurs in conidia for maintenance. Upon triggering of spore germination, generation of CO2 increased dramatically. For a short period, which coincided with mobilisation of the intracellular polyol, trehalose, there was no increase in uptake of O2 indicating that trehalose was metabolised by fermentation. Data from genome-wide mRNA profiling showed the presence of transcripts associated with fermentative and respiratory metabolism in resting conidia. Following triggering of conidial outgrowth, there was a clear switch to respiration after 25min, confirmed by cyanide inhibition. No effect of SHAM, salicylhydroxamic acid, on respiration suggests electron flow via cytochrome c oxidase. Glucose entry into spores was not detectable before 1h after triggering germination. The impact of sorbic acid on germination was examined and we showed that it inhibits glucose uptake. O2 uptake was also inhibited, delaying the onset of respiration and extending the period of fermentation. In conclusion, we show that conidia suspended in water are not completely dormant and that conidial outgrowth involves fermentative metabolism that precedes respiration. PMID:27378203

  13. Production of Conidia by the Fungus Metarhizium anisopliae Using Solid-State Fermentation.

    PubMed

    Loera-Corral, Octavio; Porcayo-Loza, Javier; Montesinos-Matias, Roberto; Favela-Torres, Ernesto

    2016-01-01

    This chapter describes the production of conidia by Metarhizium anisopliae using solid-state fermentation. Before production of conidia, procedures for strains conservation, reactivation, and propagation are essential in order to provide genetic stability of the strains. The strain is conserved in freeze-dried vials and then reactivated through insect inoculation. Rice is used as a substrate for the conidia production in two different bioreactors: plastic bags and tubular bioreactor. The CO2 production in the tubular bioreactors is measured with a respirometer; this system allows calculating indirect growth parameters as lag time (tlag) (25-35 h), maximum rate of CO2 production (rCO2 max) (0.5-0.7 mg/gdm h), specific rate of CO2 production (μ) (0.10-0.15 1/h), and final CO2 production (CO2) (100-120 mg/gdm). Conidial yield per gram of dry substrate (gdm) should be above 1 × 10(9) conidia/gdm after 10 days of incubation. Germination and viability of conidia obtained after 10 days of incubation should be above 80 % and 75 %, respectively. Bioassays using of Tenebrio molitor as a host insect should yield a final mortality above 80 %. PMID:27565492

  14. Filter Paper Degrading Ability of a Trichoderma Strain With Multinucleate Conidia

    NASA Astrophysics Data System (ADS)

    Toyama, Hideo; Yano, Makiko; Hotta, Takeshi; Toyama, Nobuo

    The multinucleate conidia were produced from the green mature conidia of Trichoderma reesei Rut C-30 strain by colchicine treatment. The strain with higher Filter paper degrading ability was selected among those conidia using a double layer selection medium. The selected strain, JS-2 was able to collapse the filter paper within 15 min but the original strain took 25 min to collapse it completely. Moreover, the amount of reducing sugar in the L-type glass tube of the strain, JS-2, was greater than that of the original strain. The Avicel, CMC-Na, and Salicin hydrolyzing activity of the strain, JS-2, increased 2.1 times, 1.2 times, and 3.6 times higher than that of the original strain.

  15. A murine inhalation model to characterize pulmonary exposure to dry Aspergillus fumigatus conidia.

    PubMed

    Buskirk, Amanda D; Green, Brett J; Lemons, Angela R; Nayak, Ajay P; Goldsmith, W Travis; Kashon, Michael L; Anderson, Stacey E; Hettick, Justin M; Templeton, Steven P; Germolec, Dori R; Beezhold, Donald H

    2014-01-01

    Most murine models of fungal exposure are based on the delivery of uncharacterized extracts or liquid conidia suspensions using aspiration or intranasal approaches. Studies that model exposure to dry fungal aerosols using whole body inhalation have only recently been described. In this study, we aimed to characterize pulmonary immune responses following repeated inhalation of conidia utilizing an acoustical generator to deliver dry fungal aerosols to mice housed in a nose only exposure chamber. Immunocompetent female BALB/cJ mice were exposed to conidia derived from Aspergillus fumigatus wild-type (WT) or a melanin-deficient (Δalb1) strain. Conidia were aerosolized and delivered to mice at an estimated deposition dose of 1×105 twice a week for 4 weeks (8 total). Histopathological and immunological endpoints were assessed 4, 24, 48, and 72 hours after the final exposure. Histopathological analysis showed that conidia derived from both strains induced lung inflammation, especially at 24 and 48 hour time points. Immunological endpoints evaluated in bronchoalveolar lavage fluid (BALF) and the mediastinal lymph nodes showed that exposure to WT conidia led to elevated numbers of macrophages, granulocytes, and lymphocytes. Importantly, CD8+ IL17+ (Tc17) cells were significantly higher in BALF and positively correlated with germination of A. fumigatus WT spores. Germination was associated with specific IgG to intracellular proteins while Δalb1 spores elicited antibodies to cell wall hydrophobin. These data suggest that inhalation exposures may provide a more representative analysis of immune responses following exposures to environmentally and occupationally prevalent fungal contaminants. PMID:25340353

  16. A Murine Inhalation Model to Characterize Pulmonary Exposure to Dry Aspergillus fumigatus Conidia

    PubMed Central

    Buskirk, Amanda D.; Green, Brett J.; Lemons, Angela R.; Nayak, Ajay P.; Goldsmith, W. Travis; Kashon, Michael L.; Anderson, Stacey E.; Hettick, Justin M.; Templeton, Steven P.; Germolec, Dori R.; Beezhold, Donald H.

    2014-01-01

    Most murine models of fungal exposure are based on the delivery of uncharacterized extracts or liquid conidia suspensions using aspiration or intranasal approaches. Studies that model exposure to dry fungal aerosols using whole body inhalation have only recently been described. In this study, we aimed to characterize pulmonary immune responses following repeated inhalation of conidia utilizing an acoustical generator to deliver dry fungal aerosols to mice housed in a nose only exposure chamber. Immunocompetent female BALB/cJ mice were exposed to conidia derived from Aspergillus fumigatus wild-type (WT) or a melanin-deficient (Δalb1) strain. Conidia were aerosolized and delivered to mice at an estimated deposition dose of 1×105 twice a week for 4 weeks (8 total). Histopathological and immunological endpoints were assessed 4, 24, 48, and 72 hours after the final exposure. Histopathological analysis showed that conidia derived from both strains induced lung inflammation, especially at 24 and 48 hour time points. Immunological endpoints evaluated in bronchoalveolar lavage fluid (BALF) and the mediastinal lymph nodes showed that exposure to WT conidia led to elevated numbers of macrophages, granulocytes, and lymphocytes. Importantly, CD8+ IL17+ (Tc17) cells were significantly higher in BALF and positively correlated with germination of A. fumigatus WT spores. Germination was associated with specific IgG to intracellular proteins while Δalb1 spores elicited antibodies to cell wall hydrophobin. These data suggest that inhalation exposures may provide a more representative analysis of immune responses following exposures to environmentally and occupationally prevalent fungal contaminants. PMID:25340353

  17. Germination of conidia of Aspergillus niger is accompanied by major changes in RNA profiles

    PubMed Central

    van Leeuwen, M.R.; Krijgsheld, P.; Bleichrodt, R.; Menke, H.; Stam, H.; Stark, J.; Wösten, H.A.B.; Dijksterhuis, J.

    2013-01-01

    The transcriptome of conidia of Aspergillus niger was analysed during the first 8 h of germination. Dormant conidia started to grow isotropically two h after inoculation in liquid medium. Isotropic growth changed to polarised growth after 6 h, which coincided with one round of mitosis. Dormant conidia contained transcripts from 4 626 genes. The number of genes with transcripts decreased to 3 557 after 2 h of germination, after which an increase was observed with 4 780 expressed genes 8 h after inoculation. The RNA composition of dormant conidia was substantially different than all the subsequent stages of germination. The correlation coefficient between the RNA profiles of 0 h and 8 h was 0.46. They were between 0.76–0.93 when profiles of 2, 4 and 6 h were compared with that of 8 h. Dormant conidia were characterised by high levels of transcripts of genes involved in the formation of protecting components such as trehalose, mannitol, protective proteins (e.g. heat shock proteins and catalase). Transcripts belonging to the Functional Gene Categories (FunCat) protein synthesis, cell cycle and DNA processing and respiration were over-represented in the up-regulated genes at 2 h, whereas metabolism and cell cycle and DNA processing were over-represented in the up-regulated genes at 4 h. At 6 h and 8 h no functional gene classes were over- or under-represented in the differentially expressed genes. Taken together, it is concluded that the transcriptome of conidia changes dramatically during the first two h and that initiation of protein synthesis and respiration are important during early stages of germination. PMID:23449598

  18. Morphological Transition of Paracoccidioides brasiliensis Conidia to Yeast Cells: In Vivo Inhibition in Females

    PubMed Central

    Aristizabal, Beatriz H.; Clemons, Karl V.; Stevens, David A.; Restrepo, Angela

    1998-01-01

    Clinical paracoccidioidomycosis is 13 times more common in men than in women. Estrogen inhibits the transition of mycelia or conidia (the saprophytic form of Paracoccidoides brasiliensis) to yeasts (the parasitic form) in vitro. Here, we show that, in male mice that were infected intranasally (mimicking natural infection) the transition of conidia in bronchoalveolar lavage fluids to intermediate forms and yeasts occurred over 24 to 96 h; CFU and yeasts (shown by histopathology) increased subsequently. In females, transition did not occur and infection cleared. These events in vivo are consistent with epidemiological and in vitro observations, suggesting that female hormones block transition and are responsible for resistance. PMID:9784579

  19. Conidia of Alternaria in the atmosphere of the city of Cordoba, Spain in relation to meteorological parameters

    NASA Astrophysics Data System (ADS)

    Angulo-Romero, J.; Mediavilla-Molina, Ana; Domínguez-Vilches, Eugenio

    In this study, we have analyzed the presence of conidia belonging to different species of the genus Alternaria in the atmosphere of the city of Cordoba, using a Hirst sampler. The results show that spores of this genus are present all year, with a clear seasonal pattern which shows two peaks, one in spring and the other in fall. A total of 26,822 conidia/m3 have been sampled, which implies a daily mean of 74.3 conidia/m3. Statistical analyses comparing the data with meteorological parameters show a positive correlation with maximum, minimum and mean temperatures, and a negative correlation with rain. Nevertheless, meteorological parameters seem to affect the number of conidia differently according to the season of the year. Regression analyses carried out in order to obtain a predictive pattern show that the best fit is between the 7-day running mean of the number of conidia and a week's accumulated mean temperature.

  20. Optimization of compatible non-ionic surfactant for formulation development of hydrophobic conidia of entomopathogenic fungi, Beauveria bassiana (Hypocreales:Cordycipitaceae) and Metarhizium anisopliae Hypocreales:Clavicipita

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aerial conidia, especially dried conidia of entomopathogenic fungi, Beauveria bassiana and Metarhizium anisopliae are hydrophobic, and therefore surfactants are needed for developing water-based formulations in laboratory studies, greenhouse bioassays, and field trials as well as commercial product ...

  1. Human Neutrophils Use Different Mechanisms To Kill Aspergillus fumigatus Conidia and Hyphae: Evidence from Phagocyte Defects.

    PubMed

    Gazendam, Roel P; van Hamme, John L; Tool, Anton T J; Hoogenboezem, Mark; van den Berg, J Merlijn; Prins, Jan M; Vitkov, Ljubomir; van de Veerdonk, Frank L; van den Berg, Timo K; Roos, Dirk; Kuijpers, Taco W

    2016-02-01

    Neutrophils are known to play a pivotal role in the host defense against Aspergillus infections. This is illustrated by the prevalence of Aspergillus infections in patients with neutropenia or phagocyte functional defects, such as chronic granulomatous disease. However, the mechanisms by which human neutrophils recognize and kill Aspergillus are poorly understood. In this work, we have studied in detail which neutrophil functions, including neutrophil extracellular trap (NET) formation, are involved in the killing of Aspergillus fumigatus conidia and hyphae, using neutrophils from patients with well-defined genetic immunodeficiencies. Recognition of conidia involves integrin CD11b/CD18 (and not dectin-1), which triggers a PI3K-dependent nonoxidative intracellular mechanism of killing. When the conidia escape from early killing and germinate, the extracellular destruction of the Aspergillus hyphae needs opsonization by Abs and involves predominantly recognition via Fcγ receptors, signaling via Syk, PI3K, and protein kinase C to trigger the production of toxic reactive oxygen metabolites by the NADPH oxidase and myeloperoxidase. A. fumigatus induces NET formation; however, NETs did not contribute to A. fumigatus killing. Thus, our findings reveal distinct killing mechanisms of Aspergillus conidia and hyphae by human neutrophils, leading to a comprehensive insight in the innate antifungal response. PMID:26718340

  2. Chlamydospore Induction from Conidia of Cylindrocarpon destructans Isolated from Ginseng in Korea.

    PubMed

    Kang, Yunhee; Kim, Mi Ran; Kim, Ki Hong; Lee, Jungkwan; Lee, Seung-Ho

    2016-03-01

    Cylindrocarpon destructans causes root rot disease in ginseng and can survive for a long time, producing chlamydospores. We optimized conditions to induce chlamydospore production from the conidia of C. destructans, isolated from Korean ginseng. This will provide the basis for testing the efficacy of control agents targeting these chlamydospores. PMID:27103857

  3. Chlamydospore Induction from Conidia of Cylindrocarpon destructans Isolated from Ginseng in Korea

    PubMed Central

    Kang, Yunhee; Kim, Mi Ran; Kim, Ki Hong

    2016-01-01

    Cylindrocarpon destructans causes root rot disease in ginseng and can survive for a long time, producing chlamydospores. We optimized conditions to induce chlamydospore production from the conidia of C. destructans, isolated from Korean ginseng. This will provide the basis for testing the efficacy of control agents targeting these chlamydospores. PMID:27103857

  4. Evaluation of Soyscreen in an Oil-based Formulation for UV Protection of Beauveria bassiana Conidia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    SoyScreen oil was studied as a formulation ingredient to protect Beauveria bassiana (Balsamo) Vuillemin conidia from UV degradation. Feruloylated soy glycerides, referred to as SoyScreen oil, are biobased ultraviolet-absorbing molecules made by combining molecules of soybean oil with ferulic acid. ...

  5. Metacridamides A and B, bioactive macrocycles from conidia of the entomopathogenic fungus Metarhizium acridum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Metarhizium acridum, an entomopathogenic fungus, has been commercialized and used successfully for biocontrol of grasshopper pests in Africa and Australia. Its conidia produce two novel 17-membered macrocycles, metacridamides A (1) and B (2), which consist of a Phe unit condensed with a nonaketide....

  6. Interactions of Aspergillus fumigatus Conidia with Airway Epithelial Cells: A Critical Review

    PubMed Central

    Croft, Carys A.; Culibrk, Luka; Moore, Margo M.; Tebbutt, Scott J.

    2016-01-01

    Aspergillus fumigatus is an environmental filamentous fungus that also acts as an opportunistic pathogen able to cause a variety of symptoms, from an allergic response to a life-threatening disseminated fungal infection. The infectious agents are inhaled conidia whose first point of contact is most likely to be an airway epithelial cell (AEC). The interaction between epithelial cells and conidia is multifaceted and complex, and has implications for later steps in pathogenesis. Increasing evidence has demonstrated a key role for the airway epithelium in the response to respiratory pathogens, particularly at early stages of infection; therefore, elucidating the early stages of interaction of conidia with AECs is essential to understand the establishment of infection in cohorts of at-risk patients. Here, we present a comprehensive review of the early interactions between A. fumigatus and AECs, including bronchial and alveolar epithelial cells. We describe mechanisms of adhesion, internalization of conidia by AECs, the immune response of AECs, as well as the role of fungal virulence factors, and patterns of fungal gene expression characteristic of early infection. A clear understanding of the mechanisms involved in the early establishment of infection by A. fumigatus could point to novel targets for therapy and prophylaxis. PMID:27092126

  7. Absorbing film assisted laser induced forward transfer of fungi (Trichoderma conidia)

    NASA Astrophysics Data System (ADS)

    Hopp, B.; Smausz, T.; Antal, Zs.; Kresz, N.; Bor, Zs.; Chrisey, D.

    2004-09-01

    We present an investigation on absorbing film assisted laser induced forward transfer (AFA-LIFT) of fungus (Trichoderma) conidia. A KrF excimer laser beam [λ =248nm,FWHM=30ns (FWHM, full width at half maximum)] was directed through a quartz plate and focused onto its silver coated surface where conidia of the Trichoderma strain were uniformly spread. The laser fluence was varied in the range of 0-2600mJ/cm2 and each laser pulse transferred a pixel of target material. The average irradiated area was 8×10-2mm2. After the transfer procedure, the yeast extract medium covered glass slide and the transferred conidia patterns were incubated for 20 h and then observed using an optical microscope. The transferred conidia pixels were germinated and the areas of the culture medium surfaces covered by the pixels were evaluated as a function of laser fluence. As the laser fluence was increased from 0 to 355mJ/cm2 the transferred and germinated pixel area increased from 0 to 0.25mm2. Further increase in fluence resulted in a drastic decrease down to an approximately constant value of 0.06mm2. The yield of successful transfer by AFA-LIFT and germination was as much as 75% at 355mJ/cm2. The results prove that AFA-LIFT can successfully be applied for the controlled transfer of biological objects.

  8. Maturation feeding and transmission of Bursaphelenchus xylophilus (Nematoda: Parasitaphelenchidae) by Monochamus alternatus (Coleoptera: Cerambycidae) inoculated with Beauveria bassiana (Deuteromycotina: Hyphomycetes).

    PubMed

    Maehara, Noritoshi; He, Xueyou; Shimazu, Mitsuaki

    2007-02-01

    We examined the amount of maturation feeding and transmission of pinewood nematodes, Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle (Nematoda: Parasitaphelenchidae), to healthy pine (Pinus spp.) trees by pine sawyer Monochamus alternatus Hope (Coleoptera: Cerambycidae) adults infected with Beauveria bassiana (Balsamo) Vuill. (Deuteromycotina: Hyphomycetes). Inoculated beetles fed less than noninoculated beetles, probably because feeding by inoculated beetles began to decrease at about 4 d postinoculation and inoculated beetles ceased to feed for several days before their death. In inoculated beetles carrying >1,000 nematodes, some beetles died before nematode departure. The remaining heavily nematode-infested beetles lived until the beginning of nematode departure, but they had stopped feeding, preventing the nematodes from entering pine twigs. We suggest that microbial control of pine sawyer adults by B. bassiana may be effective in preventing transmission of pine wilt disease to healthy pine trees. PMID:17370808

  9. Citric acid production using immobilized conidia of Aspergillus niger TMB 2022

    SciTech Connect

    Tsay, S.S.; To, K.Y.

    1987-02-20

    Conidia of Aspergillus niger TMB 2022 were immobilized in calcium alginate for the production of citric acid. A 1-ml condidia suspension containing ca. 2.32 x 10/sup 8/ conidia were entrapped into sodium alginate solution in order to prepare 3% Ca-alginate (w/v) gel bead. Immobilized conidia were inoculated into productive medium containing 14% sucrose, 0.25% (NH/sub 4/)/sub 2/CO/sub 3/, 0.25% KH/sub 2/PO/sub 4/, and 0.025% MgSO/sub 4/.7H/sub 2/O with addition of 0.06 mg/l CuSO/sub 4/.5H/sub 2/O, 0.25 mg/l ZnCl/sub 2/, 1.3 mg/l FeCl/sub 3/.6H/sub 2/O, pH 3.8, and incubated at 35 degrees C for 13 days by surface culture to produce 61.53 g/l anhydrous citric acid. Under the same conditions with a batchwise culture, it was found that immobilized conidia could maintain a longer period for citric acid production (31 days): over 70 g/l anhydrous citric acid from runs No. 2-4, with the maximum yield for anhydrous citric acid reaching 77.02 g/l for run No. 2. In contrast, free conidia maintained a shorter acid-producing phase, circa 17 days; the maximum yield for anhydrous citric acid was 71.07 g/l for run No. 2 but dropped quickly as the run number increased. 14 references.

  10. Debilitation in conidia of the entomopathogenic fungi Beauveria and Metarhizium anisopliae and implications with respect to viability determinations and mycopesticide quality assessments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Viabilities of entomopathogenic fungal conidia comprising biopesticide products are most commonly determined by suspension of dry conidia from storage in a water/surfactant solution immediately before inoculation onto an agar-based germination substrate; conidia are then incubated at a moderate temp...

  11. A new species of Cladophialophora (hyphomycetes) from boreal and montane bryophytes.

    PubMed

    Davey, Marie L; Currah, Randolph S

    2007-01-01

    During a survey of bryophilous fungi from boreal and montane habitats in central Alberta, a hitherto undescribed species of Cladophialophora was recovered from Polytrichum juniperinum, Aulacomnium palustre, and Sphagnum fuscum. On potato dextrose agar (PDA) colonies grew slowly, attaining a diameter of 25 mm after 30 d, were dark grey, velvety, radially sulcate, and convolute and cracked at the centre. Micronematous conidiophores gave rise to branched chains of small (1-2 x 8-22 microm), cylindrical to fusiform conidia with truncate, swollen scars at each end. Phylogenies built on the ITS and ribosomal SSU regions indicate the isolates form a monophyletic clade within the family Herpotrichiellaceae (Chaetothyriales) that is composed of two geographically based groups, each with 99% within-group sequence similarity and 97-98% between-group sequence similarity. A teleomorph has not been found but would likely be similar to species of Capronia. In vitro inoculation of the isolates onto axenically grown P. juniperinum produced no discernible host symptoms, and host penetration could not be detected using light microscopy. The production of polyphenol oxidases by the fungus and the role of other Cladophialophora species as latent endophytes and saprobes suggest that a potential role for the fungus is the degradation of the polyphenol-rich cell walls of mosses. A dichotomous key to species of the genus Cladophialophora is provided. PMID:17169546

  12. Association of a Myosin Immunoanalogue with Cell Envelopes of Aspergillus fumigatus Conidia and Its Participation in Swelling and Germination

    PubMed Central

    Esnault, Karine; el Moudni, Brahim; Bouchara, Jean-Philippe; Chabasse, Dominique; Tronchin, Guy

    1999-01-01

    A myosin immunoanalogue was identified in conidia of Aspergillus fumigatus by Western blotting, indirect immunofluorescence assay, and gold immunoelectron microscopy with two different antimyosin antibodies. The distribution pattern of this protein was followed during the early stages of germination. A single 180-kDa polypeptide, detected predominantly in a cell envelope extract, was found to cross-react with monoclonal and polyclonal antibodies raised against vertebrate muscle myosin. Immunoelectron microscopy permitted precise localization of this polypeptide, indicating that myosin analogue was mainly distributed along the plasma membrane of resting and swollen conidia. In germinating conidia, indirect immunofluorescence microscopy revealed myosin analogue at the periphery of germ tubes, whereas actin appeared as dispersed punctate structures in the cytoplasm that were more concentrated at the site of germ tube emergence. A myosin ATPase inhibitor, butanedione monoxime, greatly reduced swelling and blocked germination. In contrast, when conidia were treated with cytochalasin B, an inhibitor of actin polymerization, swelling was not affected and germination was only partially reduced. Butanedione monoxime-treated conidia showed accumulation of cytoplasmic vesicles and did not achieve cell wall reorganization, unlike swollen conidia. Collectively, these results suggest an essential role for this myosin analogue in the deposition of cell wall components during germination of A. fumigatus conidia and therefore in host tissue colonization. PMID:10024566

  13. New solid-state fermentation chamber for bulk production of aerial conidia of fungal biocontrol agents on rice.

    PubMed

    Ye, S D; Ying, S H; Chen, C; Feng, M G

    2006-06-01

    A novel solid-state fermentation apparatus, namely an upright multi-tray conidiation chamber, was developed to facilitate the production of aerial conidia of fungal biocontrol agents, such as Beauveria bassiana. The chamber with 25 bottom-meshed metal trays had a capacity of > or =50 kg rice with each tray holding > or =2 kg. In repeated trials, a mean yield of 2.4 (1.8-2.7) x 10(12) conidia kg(-1) rice was harvested from the 7-day cultures of B. bassiana in a fully loaded chamber. The new apparatus has a high potential for bulk production of fungal conidia. PMID:16786244

  14. Evaluation of Beauveria bassiana (hyphomycetes) strains as potential agents for control of Triatoma infestans (Hemiptera: Reduviidae).

    PubMed

    Lecuona, R E; Edelstein, J D; Berretta, M F; La Rossa, F R; Arcas, J A

    2001-03-01

    Chagas disease constitutes a major human health problem in most Latin American countries. This endemic disease is transmitted by several species of triatomine bugs, the most important being Triatoma infestans (Klug). In this article, we report on the selection of strains of the entomopathogenic fungus Beauveria bassiana (Bals.) Vuill. virulent to T. infestans for possible use as bioinsecticides. Four strains of B. hassiana isolated from Argentina (Bb 1, 10, 25, and 65) were evaluated. To calculate mortality and mean lethal time, nymphs and adults of T. infestans were treated with conidia produced on complete agar medium and wheat brain and rice husk medium (WH). The LD50 for nymphs and adults of T. infestans was calculated. The effect of different temperatures (18, 22, 26, 30, and 34 degrees C) and relative humidities (35 and 90% RH) on mortality of nymphs were studied. We evaluated the compatibility of strains with Deltamethrin and Beta-Cypermethrin. Although the strain Bb 25 failed to grow on WH, the other three strains showed similar mortality values independent of the culture medium used to grow the microorganisms. The lowest LD50 values for nymphs were obtained with the strains Bb 10 and 65 and for adults were Bb 1, 10, and 65. The highest mean mortality was obtained with strain Bb 10, and among temperatures the highest mean mortality was observed at 26 degrees C. Relative humidity did not affect the mortality of T. infestans nymphs with all strains and temperatures assayed. Deltamethrin did not affect any of the three strains for the four studied doses, and Beta-Cypermethrin could be used in combination with the fungus only at low doses. The strain Bb 10 was selected for future assays under natural climatic conditions. PMID:11296819

  15. In vitro photodynamic inactivation of conidia of the phytopathogenic fungus Colletotrichum graminicola with cationic porphyrins.

    PubMed

    Vandresen, Camila Chevonica; Gonçalves, Alan Guilherme; Ducatti, Diogo Ricardo Bazan; Murakami, Fabio Seigi; Noseda, Miguel Daniel; Duarte, Maria Eugenia Rabello; Barreira, Sandra Mara Woranovicz

    2016-05-11

    Photodynamic inactivation (PDI) is an efficient approach for the elimination of a series of microorganisms; however, PDI involving phytopathogenic filamentous fungi is scarce in the literature. In the present study, we have demonstrated the photoinactivating properties of five cationic meso-(1-methyl-4-pyridinio)porphyrins on conidia of the phytopathogen Colletotrichum graminicola. For this purpose, photophysical properties (photostability and (1)O2 singlet production) of the porphyrins under study were first evaluated. PDI assays were then performed with a fluence of 30, 60, 90 and 120 J cm(-2) and varying the porphyrin concentration from 1 to 25 μmol L(-1). Considering the lowest concentration that enabled the best photoinactivation, with the respective lowest effective irradiation time, the meso-(1-methyl-4-pyridinio)porphyrins herein studied could be ranked as follows: triple-charged 4 (1 μmol L(-1) with a fluence of 30 J cm(-2)) > double-charged-trans2 (1 μmol L(-1) with 60 J cm(-2)) > tetra-charged 5 (15 μmol L(-1) with 90 J cm(-2)) > mono-charged 1 (25 μmol L(-1) with 120 J cm(-2)). Double-charged-cis-porphyrin 3 inactivated C. graminicola conidia in the absence of light. Evaluation of the porphyrin binding to the conidia and fluorescence microscopic analysis were also performed, which were in agreement with the PDI results. In conclusion, the cationic porphyrins herein studied were considered efficient photosensitizers to inactivate C. graminicola conidia. The amount and position of positive charges are related to the compounds' amphiphilicity and therefore to their photodynamic activity. PMID:27109559

  16. EVALUATION OF DIFFERENT METHODS FOR THE EXTRACTION OF DNA FROM FUNGAL CONIDIA BY QUANTITATIVE COMPETITIVE PCR ANALYSIS

    EPA Science Inventory

    Five different DNA extraction methods were evaluated for their effectiveness in recovering PCR templates from the conidia of a series of fungal species often encountered in indoor air. The test organisms were Aspergillus versicolor, Penicillium chrysogenum, Stachybotrys chartaru...

  17. Location of Aryl Sulfatase in Conidia and Young Mycelia of Neurospora crassa

    PubMed Central

    Scott, Walter A.; Metzenberg, Robert L.

    1970-01-01

    Aryl sulfatase (arylsulfate sulfohydrolase, EC 3.1.6.1) was found to have multiple locations in Neurospora conidia. Some enzyme activity remained in the supernatant when a spore suspension was centrifuged or filtered. Part of the cell-bound activity could be detected by adding the assay ingredients to a suspension of intact spores (patent enzyme), and additional activity was only detectable when the spores were first treated to destroy their permeability barriers (cryptic enzyme). Such treatments include: disruption with an X-press, brief rinsing with chloroform or acetone, incubation at 60 C for 5 min, and incubation with phenethyl alcohol, nystatin, or ascosin. Part of the patent aryl sulfatase was inactivated by briefly acid treating the intact spores (no loss of conidial viability). This enzyme was considered to have a cell surface location. Some enzyme was acid-resistant in intact spores, but all of the enzyme was acid-sensitive in spores whose permeability barriers had been disrupted. The pH dependence, kinetic properties, and p-nitrophenyl sulfate uptake were investigated in acid-treated conidia. No aryl sulfatase was detected in ascospores. Young mycelia contained more aryl sulfatase than did conidia, but little, if any, was secreted into the growth medium. Cryptic activity was demonstrated in young mycelia by brief chloroform treatment or by rinsing the cells with 0.1 m acetate buffer. Enzyme activity in young mycelia was completely labile to acid treatment, as was cell viability. PMID:16559101

  18. The effect of natamycin on the transcriptome of conidia of Aspergillus niger

    PubMed Central

    van Leeuwen, M.R.; Krijgsheld, P.; Wyatt, T.T.; Golovina, E.A.; Menke, H.; Dekker, A.; Stark, J.; Stam, H.; Bleichrodt, R.; Wösten, H.A.B.; Dijksterhuis, J.

    2013-01-01

    The impact of natamycin on Aspergillus niger was analysed during the first 8 h of germination of conidia. Polarisation, germ tube formation, and mitosis were inhibited in the presence of 3 and 10 μM of the anti-fungal compound, while at 10 μM also isotropic growth was affected. Natamycin did not have an effect on the decrease of microviscosity during germination and the concomitant reduction in mannitol and trehalose levels. However, it did abolish the increase of intracellular levels of glycerol and glucose during the 8 h period of germination. Natamycin hardly affected the changes that occur in the RNA profile during the first 2 h of germination. During this time period, genes related to transcription, protein synthesis, energy and cell cycle and DNA processing were particularly up-regulated. Differential expression of 280 and 2586 genes was observed when 8 h old germlings were compared with conidia that had been exposed to 3 μM and 10 μM natamycin, respectively. For instance, genes involved in ergosterol biosynthesis were down-regulated. On the other hand, genes involved in endocytosis and the metabolism of compatible solutes, and genes encoding protective proteins were up-regulated in natamycin treated conidia. PMID:23449730

  19. Ecological study of Paracoccidioides brasiliensis in soil: growth ability, conidia production and molecular detection

    PubMed Central

    Terçarioli, Gisela Ramos; Bagagli, Eduardo; Reis, Gabriela Martins; Theodoro, Raquel Cordeiro; Bosco, Sandra De Moraes Gimenes; Macoris, Severino Assis da Graça; Richini-Pereira, Virgínia Bodelão

    2007-01-01

    Background Paracoccidioides brasiliensis ecology is not completely understood, although several pieces of evidence point to the soil as its most probable habitat. The present study aimed to investigate the fungal growth, conidia production and molecular pathogen detection in different soil conditions. Methods Soils samples of clayey, sandy and medium textures were collected from ground surface and the interior of armadillo burrows in a hyperendemic area of Paracoccidioidomycosis. P. brasiliensis was inoculated in soil with controlled humidity and in culture medium containing soil extracts. The molecular detection was carried out by Nested PCR, using panfungal and species specific primers from the ITS-5.8S rDNA region. Results The soil texture does not affect fungus development and the growth is more abundant on/in soil saturated with water. Some soil samples inhibited the development of P. brasiliensis, especially those that contain high values of Exchangeable Aluminum (H+Al) in their composition. Some isolates produced a large number of conidia, mainly in soil-extract agar medium. The molecular detection was positive only in samples collected from armadillo burrows, both in sandy and clayey soil. Conclusion P. brasiliensis may grow and produce the infectious conidia in sandy and clayey soil, containing high water content, mainly in wild animal burrows, but without high values of H+Al. PMID:17953742

  20. Differential Regulation by Organic Compounds and Heavy Metals of Multiple Laccase Genes in the Aquatic Hyphomycete Clavariopsis aquatica

    PubMed Central

    Solé, Magali; Müller, Ines; Pecyna, Marek J.; Fetzer, Ingo; Harms, Hauke

    2012-01-01

    To advance the understanding of the molecular mechanisms controlling microbial activities involved in carbon cycling and mitigation of environmental pollution in freshwaters, the influence of heavy metals and natural as well as xenobiotic organic compounds on laccase gene expression was quantified using quantitative real-time PCR (qRT-PCR) in an exclusively aquatic fungus (the aquatic hyphomycete Clavariopsis aquatica) for the first time. Five putative laccase genes (lcc1 to lcc5) identified in C. aquatica were differentially expressed in response to the fungal growth stage and potential laccase inducers, with certain genes being upregulated by, e.g., the lignocellulose breakdown product vanillic acid, the endocrine disruptor technical nonylphenol, manganese, and zinc. lcc4 is inducible by vanillic acid and most likely encodes an extracellular laccase already excreted during the trophophase of the organism, suggesting a function during fungal substrate colonization. Surprisingly, unlike many laccases of terrestrial fungi, none of the C. aquatica laccase genes was found to be upregulated by copper. However, copper strongly increases extracellular laccase activity in C. aquatica, possibly due to stabilization of the copper-containing catalytic center of the enzyme. Copper was found to half-saturate laccase activity already at about 1.8 μM, in favor of a fungal adaptation to low copper concentrations of aquatic habitats. PMID:22544244

  1. Virulence of Sporothrix schenckii conidia and yeast cells, and their susceptibility to nitric oxide

    PubMed Central

    Fernandes, K S S; Coelho, A L J; Bezerra, L M Lopes; Barja-Fidalgo, C

    2000-01-01

    The involvement of nitric oxide (NO) in macrophage (Mφ) fungicidal activity against Sporothrix schenckii, and the relationship between NO susceptibility and the differential virulence of conidia and yeast cells, were investigated. Confirming a previously reported correlation between the length of time in culture and virulence of S. schenckii, conidia isolated from 12-day mycelial cultures (Ss-12) were less virulent to mice than conidia from 7-day cultures (Ss-7) or yeast cells. Indicative of NO production, infected animals showed a significant increase in serum levels of nitrite that was lower in mice infected with Ss-12 than in mice infected with Ss-7 or yeast. Stimulation of murine Mφ with interferon-γ (IFN-γ) induced NO production and inhibition of fungal growth. The cytotoxic activity of Mφ against Ss-12 was significantly greater than against Ss-7 or yeast cells, the highly virulent fungal forms. The addition of NO synthase inhibitors abrogated Mφ cytotoxic activity against all fungal forms. The phagocytic activity of Mφ against Ss-7 was significantly lower than against Ss-12 or yeast cells. Although the ingestion of fungal cells triggered the oxidative burst in Mφ, the fungicidal activity was not altered in the presence of superoxide dismutase (SOD) and catalase. In addition, Ss-12 and yeast cells were more susceptible than Ss-7 to the direct fungicidal activity of the NO donors S-nitroso-N-acetyl-dl-penicillamine (SNAP), S-nitrosoglutathione (GSNO) and 3-morpholinosydnonimine (SIN-1). The results of this study indicate that NO is a key cytotoxic mediator involved in the murine Mφ defence against S. schenckii, and that the virulence of Ss-7, Ss-12 and yeast cells may be related to a differential susceptibility to NO. PMID:11122461

  2. Beta 1,4-oligoglucosides inhibit the binding of Aspergillus fumigatus conidia to human monocytes.

    PubMed

    Kan, V L; Bennett, J E

    1991-05-01

    The binding of Aspergillus fumigatus conidia to human monocytes is mediated by a barley beta-glucan-inhibitable receptor. The simplest linkages in this glucan are present in the disaccharides laminaribiose (beta 1,3) and cellobiose (beta 1,4). Although laminaribiose gave strong inhibition of conidial binding to monocytes, cellobiose and oligosaccharides with beta 1,4-linked glucose residues were more potent as specific inhibitors of this binding over similar concentrations. Increasing the number of beta 1,4-linked glucose residues led to greater inhibition of conidial binding by human monocytes. PMID:2019764

  3. Butyl acetate and yeasts interact in adhesion and germination of Botrytis cinerea conidia in vitro and in fungal decay of golden delicious apple.

    PubMed

    Filonow, A B

    2001-04-01

    Butyl acetate is a volatile aroma and flavor compound in apple. Conidia of three strains of Botrytis cinerea, a fungus that causes decay of apple fruit in postharvest storage, had greater adhesion to and greater germination on polycarbonate membrane filters on water inside sealed 500 cc glass jars that were injected with 4 microliters butyl acetate than conidia not so exposed. Conidial germination was highly correlated with conidial adhesion. The yeasts Sporobolomyces roseus and Cryptococcus laurentii, but not Saccharomyces cerevisiae, reduced the adhesion and germination promoting effect of butyl acetate. Conidia did not readily utilize butyl acetate as a food source, as shown by lack of tetrazolium violet reduction, whereas S. roseus and C. laurentii, but not S. cerevisiae did. Butyl acetate added to suspensions of conidia increased the electrical conductivity of the suspensions and increased the loss of 14C from 14C-labeled conidia compared to conidia unexposed to butyl acetate. Uptake of [14C]glucose by conidia was not increased by butyl acetate. Wounds of Golden Delicious apples inoculated with conidia (strain F-J-4) in a dilute solution of butyl acetate had greater decay than unexposed wounds. S. roseus and C. laurentii, but not S. cerevisiae, added with the conidia decreased the incidence or size of decay. Results indicated that butyl acetate increased conidial adhesion, stimulating conidial germination, and some yeasts can reduce this effect. PMID:11446303

  4. conF and conJ contribute to conidia germination and stress response in the filamentous fungus Aspergillus nidulans.

    PubMed

    Suzuki, Satoshi; Sarikaya Bayram, Özlem; Bayram, Özgür; Braus, Gerhard H

    2013-07-01

    Light induces various responses in fungi including formation of asexual and sexual reproductive structures. The formation of conidia in the filamentous fungus Aspergillus nidulans is regulated by red and blue light receptors. Expression of conidia associated con genes, which are widely spread in the fungal kingdom, increases upon exposure to light. We have characterized the light-inducible conF and conJ genes of A. nidulans which are homologs of con-6 and con-10 of Neurospora crassa. con genes are expressed during conidia formation in asexual development. Five minutes light exposure are sufficient to induce conF or conJ expression in vegetative mycelia. Similar to N. crassa there were no significant phenotypes of single con mutations. A double conF and conJ deletion resulted in significantly increased cellular amounts of glycerol or erythritol. This leads to a delayed germination phenotype combined with increased resistance against desiccation. These defects were rescued by complementation of the double mutant strain with either conF or conJ. This suggests that fungal con genes exhibit redundant functions in controlling conidia germination and adjusting cellular levels of substances which protect conidia against dryness. PMID:23644150

  5. A novel computerised image analysis method for the measurement of production of conidia from the aphid pathogenic fungus Erynia neoaphidis.

    PubMed

    Bonner, Tony J; Pell, Judith K; Gray, Simon N

    2003-03-14

    A semi-automated method has been developed for the quantification and measurement of conidia discharged by the aphid pathogen Erynia neoaphidis. This was used to compare conidiation by E. neoaphidis-mycosed pea aphid cadavers, mycelial plugs cut from agar plates, mycelial pellets from shake flasks and by mycelial pellets from different phases of liquid batch fermenter culture. Aphid cadavers discharged significantly more and significantly smaller conidia than plugs or pellets. The volume of conidia discharged was stable over the period of discharge (80 h), but more detailed analysis of the size frequency distribution showed that more very small and very large conidia were discharged after 5 h incubation than after 75 h incubation. Biomass harvested at the end of the exponential growth phase in batch fermenter culture produced significantly more conidia than biomass from any other growth phase. The implications of these findings for the development of production and formulation processes for E. neoaphidis as a biological control agent are discussed. PMID:12644230

  6. Conidia of the insect pathogenic fungus, Metarhizium anisopliae, fail to adhere to mosquito larval cuticle

    PubMed Central

    Greenfield, Bethany P. J.; Lord, Alex M.; Dudley, Ed; Butt, Tariq M.

    2014-01-01

    Adhesion of conidia of the insect pathogenic fungus, Metarhizium anisopliae, to the arthropod host cuticle initially involves hydrophobic forces followed by consolidation facilitated by the action of extracellular enzymes and secretion of mucilage. Gene expression analysis and atomic force microscopy were used to directly quantify recognition and adhesion between single conidia of M. anisopliae and the cuticle of the aquatic larval stage of Aedes aegypti and a representative terrestrial host, Tenebrio molitor. Gene expression data indicated recognition by the pathogen of both hosts; however, the forces for adhesion to the mosquito were approximately five times lower than those observed for Tenebrio. Although weak forces were recorded in response to Aedes, Metarhizium was unable to consolidate firm attachment. An analysis of the cuticular composition revealed an absence of long-chain hydrocarbons in Aedes larvae which are thought to be required for fungal development on host cuticle. This study provides, to our knowledge, the first evidence that Metarhizium does not form firm attachment to Ae. aegypti larvae in situ, therefore preventing the normal route of invasion and pathogenesis from occuring. PMID:26064542

  7. A Non-canonical Melanin Biosynthesis Pathway Protects Aspergillus terreus Conidia from Environmental Stress.

    PubMed

    Geib, Elena; Gressler, Markus; Viediernikova, Iuliia; Hillmann, Falk; Jacobsen, Ilse D; Nietzsche, Sandor; Hertweck, Christian; Brock, Matthias

    2016-05-19

    Melanins are ubiquitous pigments found in all kingdoms of life. Most organisms use them for protection from environmental stress, although some fungi employ melanins as virulence determinants. The human pathogenic fungus Aspergillus fumigatus and related Ascomycetes produce dihydroxynaphthalene- (DHN) melanin in their spores, the conidia, and use it to inhibit phagolysosome acidification. However, biosynthetic origin of melanin in a related fungus, Aspergillus terreus, has remained a mystery because A. terreus lacks genes for synthesis of DHN-melanin. Here we identify genes coding for an unusual NRPS-like enzyme (MelA) and a tyrosinase (TyrP) that A. terreus expressed under conidiation conditions. We demonstrate that MelA produces aspulvinone E, which is activated for polymerization by TyrP. Functional studies reveal that this new pigment, Asp-melanin, confers resistance against UV light and hampers phagocytosis by soil amoeba. Unexpectedly, Asp-melanin does not inhibit acidification of phagolysosomes, thus likely contributing specifically to survival of A. terreus conidia in acidic environments. PMID:27133313

  8. Inhibition of Pseudogymnoascus destructans growth from conidia and mycelial extension by bacterially produced volatile organic compounds.

    PubMed

    Cornelison, Christopher T; Gabriel, Kyle T; Barlament, Courtney; Crow, Sidney A

    2014-02-01

    The recently identified causative agent of white-nose syndrome (WNS), Pseudogymnoascus destructans, has been implicated in the mortality of an estimated 5.5 million North American bats since its initial documentation in 2006 (Frick et al. in Science 329:679-682, 2010). In an effort to identify potential biological and chemical control options for WNS, 6 previously described bacterially produced volatile organic compounds (VOCs) were screened for anti-P. destructans activity. The compounds include decanal; 2-ethyl-1-hexanol; nonanal; benzothiazole; benzaldehyde; andN,N-dimethyloctylamine. P. destructans conidia and mycelial plugs were exposed to the VOCs in a closed air space at 15 and 4 °C and then evaluated for growth inhibition. All VOCs inhibited growth from conidia as well as inhibiting radial mycelial extension, with the greatest effect at 4 °C. Studies of the ecology of fungistatic soils and the natural abundance of the fungistatic VOCs present in these environments suggest a synergistic activity of select VOCs may occur. The evaluation of formulations of two or three VOCs at equivalent concentrations was supportive of synergistic activity in several cases. The identification of bacterially produced VOCs with anti-P. destructans activity indicates disease-suppressive and fungistatic soils as a potentially significant reservoir of biological and chemical control options for WNS and provides wildlife management personnel with tools to combat this devastating disease. PMID:24190516

  9. Toxicity of ozone gas to conidia of Penicillium digitatum, P. italicum, and Botrytis cinerea and control of gray mold on table grapes.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Penicillium digitatum, P. italicum, and Botrytis cinerea attack fresh fruit and cause significant postharvest decay losses and the toxicity of ozone (O3) gas at different relative humidities to control their conidia was determined. Conidia were exposed to an atmosphere containing 200 to 350 µL L-1 o...

  10. Conidia production by Beauveria bassiana (for the biocontrol of a diamondback moth) during solid-state fermentation in a packed-bed bioreactor.

    PubMed

    Kang, S W; Lee, S H; Yoon, C S; Kim, S W

    2005-01-01

    Conidia of Beauveria bassiana CS-1, which have the potential for the control of the diamondback moth (Plutella xylostella), were produced by solid-state fermentation (SSF) using a packed-bed bioreactor with rice straw and wheat bran. As the packing density and the bed height were increased, the production of conidia decreased. In a packed-bed bioreactor under no aeration and no addition of polypropylene (PP) foam (control), the total average of conidia was 4.9 x 10(8) g-1. The production of conidia was affected more by the addition of PP foam as an inert support than forced aeration and was approx. 23 times higher than that of the control. The total average of conidia produced by B. bassiana was 1.1-1.2 x 10(10) g-1 . PMID:15703878

  11. Transformation of the bioherbicide Colletotrichum gloeosporioides f. sp. Aeschynomene By electroporation of germinated conidia.

    PubMed

    Robinson, M; Sharon, A

    1999-08-01

    A highly efficient and reproducible procedure for the transformation of the bioherbicide Colletotrichum gloeosporioides f. sp. aeschynomene by electroporation of germinated conidia is reported. Development of the procedure involved a detailed study of the germination process followed by extensive calibration of the electrical-pulse and selection conditions. Optimization of the transformation protocol was facilitated by the use of the green fluorescent protein that helped in the identification of stable transformants and in a fast assessment of transgene expression levels, colony homogeneity and genetic stability. Under optimal conditions, over 80 stable transformants/cuvette were obtained. Plasmid integration was predominantly homologous, but high transformation rates were obtained both with homologous and non-homologous vectors. The method described not only opens up opportunities for the genetic manipulation of C. gloeosporioides f. sp. aeschynomene, but also provides a framework for the development and optimization of transformation in other fungi. PMID:10447601

  12. A Quantitative Dynamic Simulation of Bremia lactucae Airborne Conidia Concentration above a Lettuce Canopy

    PubMed Central

    Fall, Mamadou Lamine; Van der Heyden, Hervé; Carisse, Odile

    2016-01-01

    Lettuce downy mildew, caused by the oomycete Bremia lactucae Regel, is a major threat to lettuce production worldwide. Lettuce downy mildew is a polycyclic disease driven by airborne spores. A weather-based dynamic simulation model for B. lactucae airborne spores was developed to simulate the aerobiological characteristics of the pathogen. The model was built using the STELLA platform by following the system dynamics methodology. The model was developed using published equations describing disease subprocesses (e.g., sporulation) and assembled knowledge of the interactions among pathogen, host, and weather. The model was evaluated with four years of independent data by comparing model simulations with observations of hourly and daily airborne spore concentrations. The results show an accurate simulation of the trend and shape of B. lactucae temporal dynamics of airborne spore concentration. The model simulated hourly and daily peaks in airborne spore concentrations. More than 95% of the simulation runs, the daily-simulated airborne conidia concentration was 0 when airborne conidia were not observed. Also, the relationship between the simulated and the observed airborne spores was linear. In more than 94% of the simulation runs, the proportion of the linear variation in the hourly-observed values explained by the variation in the hourly-simulated values was greater than 0.7 in all years except one. Most of the errors came from the deviation from the 1:1 line, and the proportion of errors due to the model bias was low. This model is the only dynamic model developed to mimic the dynamics of airborne inoculum and represents an initial step towards improved lettuce downy mildew understanding, forecasting and management. PMID:26953691

  13. A Quantitative Dynamic Simulation of Bremia lactucae Airborne Conidia Concentration above a Lettuce Canopy.

    PubMed

    Fall, Mamadou Lamine; Van der Heyden, Hervé; Carisse, Odile

    2016-01-01

    Lettuce downy mildew, caused by the oomycete Bremia lactucae Regel, is a major threat to lettuce production worldwide. Lettuce downy mildew is a polycyclic disease driven by airborne spores. A weather-based dynamic simulation model for B. lactucae airborne spores was developed to simulate the aerobiological characteristics of the pathogen. The model was built using the STELLA platform by following the system dynamics methodology. The model was developed using published equations describing disease subprocesses (e.g., sporulation) and assembled knowledge of the interactions among pathogen, host, and weather. The model was evaluated with four years of independent data by comparing model simulations with observations of hourly and daily airborne spore concentrations. The results show an accurate simulation of the trend and shape of B. lactucae temporal dynamics of airborne spore concentration. The model simulated hourly and daily peaks in airborne spore concentrations. More than 95% of the simulation runs, the daily-simulated airborne conidia concentration was 0 when airborne conidia were not observed. Also, the relationship between the simulated and the observed airborne spores was linear. In more than 94% of the simulation runs, the proportion of the linear variation in the hourly-observed values explained by the variation in the hourly-simulated values was greater than 0.7 in all years except one. Most of the errors came from the deviation from the 1:1 line, and the proportion of errors due to the model bias was low. This model is the only dynamic model developed to mimic the dynamics of airborne inoculum and represents an initial step towards improved lettuce downy mildew understanding, forecasting and management. PMID:26953691

  14. Thermal inactivation of Botrytis cinerea conidia in synthetic medium and strawberry puree.

    PubMed

    Villa-Rojas, R; Sosa-Morales, M E; López-Malo, A; Tang, J

    2012-04-16

    Botrytis cinerea is one of the most important post-harvest molds that cause quality deterioration of strawberries and other fruits even during refrigeration storage. This research studied the effects of thermal inactivation of B. cinerea in synthetic medium and strawberry puree using hot water baths at different temperatures. These media were studied in order to determine if results obtained in a solution with the major components of the fruit (synthetic media), are comparable to the ones obtained in fruit purees. The results demonstrated that B. cinerea spores can be inactivated by heat treatments using relatively low temperatures (42-46 °C). Inactivation curves were well described by first order kinetics (R² 0.91-0.99). B. cinerea conidia inoculated in synthetic medium required less time to achieve one log reduction in population than those inoculated in the fruit puree. D values were 22, 8.5, 4 and 1.4 min at 42, 44, 46 and 48 °C, respectively, in synthetic medium; while D values in strawberry puree were 44.9, 13.8, 4.7 and 1.4 min at 42, 44, 46 and 48 °C, respectively. The z values obtained were 4.15 and 5.08 °C for the strawberry puree and synthetic medium respectively, showing higher sensitivity of B. cinerea in fruit purees than in the synthetic medium. Thus, a change in the medium composition had a marked difference in the heat inactivation of B. cinerea conidia, and the results obtained in synthetic medium are not accurate to describe the behavior of the microorganism in the fruit. PMID:22445202

  15. QUANTIFICATION OF STACHYBOTRYS CHARTARUM CONIDIA IN INDOOR DUST USING REAL TIME, FLUORESCENT PROBE-BASED DETECTION OF PCR PRODUCTS

    EPA Science Inventory

    Analyses of fungal spores or conidia in indoor dust samples can be useful for determining the contamination status of building interiors and in signaling instances where potentially harmful exposures of building occupants to these organisms may exist. A recently developed method ...

  16. Optimization of erythritol and glycerol accumulation in conidia of Beauveria bassiana by solid-state fermentation, using response surface methodology.

    PubMed

    Tarocco, Federico; Lecuona, Roberto E; Couto, Alicia S; Arcas, Jorge A

    2005-09-01

    Entomopathogenic fungi are widely produced for use as mycoinsecticides. Therefore, improvement of the shelf life of fungal propagules under good and adverse conditions should be a pre-requisite of their production. In order to improve conidial physiology as well as mycoinsecticide efficiency, culture conditions may be varied. The Doehlert design was used to generate response surfaces with an estimation of the parameters of the quadratic model allowing the study of three different factors at a different number of levels. This experimental design was applied to optimize water activity (aw), pH, and fermentation time for Beauveria bassiana conidial production and accumulation of polyols in solid-state fermentation. Thus, it was possible to identify the region in the experimental range in which the optimum values of these parameters were simultaneously achieved. Maximal conidia production was achieved at pH 5-6 and aw=0.999. Under these conditions, polyol accumulation was 3 mg erythritol/g conidia and 29.6 mg glycerol/g conidia. However, maximal polyol accumulation was achieved at pH 4.5 and aw 0.950; erythritol production increased 33-fold and glycerol production 4.5-fold. Under these conditions conidia production was 1,000 times lower. The possibilities of increasing the quality of the biocontrol agent without neglecting yield are discussed. PMID:15731900

  17. Distinct Innate Immune Phagocyte Responses to Aspergillus fumigatus Conidia and Hyphae in Zebrafish Larvae

    PubMed Central

    Knox, Benjamin P.; Deng, Qing; Rood, Mary; Eickhoff, Jens C.

    2014-01-01

    Aspergillus fumigatus is the most common filamentous fungal pathogen of immunocompromised hosts, resulting in invasive aspergillosis (IA) and high mortality rates. Innate immunity is known to be the predominant host defense against A. fumigatus; however, innate phagocyte responses to A. fumigatus in an intact host and their contributions to host survival remain unclear. Here, we describe a larval zebrafish A. fumigatus infection model amenable to real-time imaging of host-fungal interactions in live animals. Following infection with A. fumigatus, innate phagocyte populations exhibit clear preferences for different fungal morphologies: macrophages rapidly phagocytose conidia and form aggregates around hyphae, while the neutrophil response is dependent upon the presence of hyphae. Depletion of macrophages rendered host larvae susceptible to invasive disease. Moreover, a zebrafish model of human leukocyte adhesion deficiency with impaired neutrophil function also resulted in invasive disease and impaired host survival. In contrast, macrophage-deficient but not neutrophil-deficient larvae exhibited attenuated disease following challenge with a less virulent (ΔlaeA) strain of A. fumigatus, which has defects in secondary metabolite production. Taking these results together, we have established a new vertebrate model for studying innate immune responses to A. fumigatus that reveals distinct roles for neutrophils and macrophages in mediating host defense against IA. PMID:24879123

  18. Metacridamides A and B, macrocycles from conidia of the entomopathogenic fungus Metarhizium acridum

    PubMed Central

    Krasnoff, Stuart B.; Englich, Ulrich; Miller, Paula G.; Shuler, Michael L.; Glahn, Raymond P.; Donzelli, Bruno G. G.; Gibson, Donna M.

    2012-01-01

    Metarhizium acridum, an entomopathogenic fungus, has been commercialized and used successfully for biocontrol of grasshopper pests in Africa and Australia. Its conidia produce two novel 17-membered macrocycles, metacridamides A (1) and B (2), which consist of a Phe unit condensed with a nonaketide. Planar structures were elucidated by a combination of mass spectrometric and NMR techniques. Following hydrolysis of 1, chiral amino acid analysis assigned the L-configuration to the Phe unit. A crystal structure established the absolute configuration of the eight remaining stereogenic centers in 1. Metacridamide A (1) showed cytotoxicity to three cancer lines with IC50s of 6.2, 11.0, and 10.8 µM against Caco-2 (epithelial colorectal adenocarcinoma), MCF-7 (breast cancer), and HepG2/C3A (hepatoma) cell lines, respectively. In addition, metacridamide B (2) had an IC50 of 18.2 µM against HepG2/C3A, although it was inactive at 100 µM against Caco-2 and MCF-7. Neither analogue showed antimicrobial, phytotoxic, or insecticidal activity. PMID:22292922

  19. Utilization of a Conidia-Deficient Mutant to Study Sexual Development in Fusarium graminearum

    PubMed Central

    Son, Hokyoung; Lim, Jae Yun; Lee, Yoonji; Lee, Yin-Won

    2016-01-01

    Transcriptome analysis is a widely used approach to study the molecular mechanisms underlying development and the responses of fungi to environmental cues. However, it is difficult to obtain cells with a homogeneous status from the sexually-induced culture of the plant pathogenic fungus Fusarium graminearum. In this study, we provided phenotypic and genetic evidence to show that the current conditions applied for perithecia induction inevitably highly induced asexual sporulation in this fungus. We also found that hundreds of genes under the control of the conidiation-specific gene ABAA were unnecessarily upregulated after perithecia induction. Deletion of ABAA specifically blocked conidia production in both the wild-type strain and sexually-defective mutants during sexual development. Taken together, our results suggest that the abaA strain could be used as a background strain for studies of the initial stages of perithecia production in F. graminearum. Further comparative transcriptome analysis between the abaA mutant and the sexually-defective transcription factor mutant carrying the ABAA deletion would contribute to the construction of the genetic networks involved in perithecia development in F. graminearum. PMID:27175901

  20. Nitric Oxide Participation in the Fungicidal Mechanism of Gamma Interferon-Activated Murine Macrophages against Paracoccidioides brasiliensis Conidia

    PubMed Central

    Gonzalez, Angel; de Gregori, Waldemar; Velez, Diana; Restrepo, Angela; Cano, Luz E.

    2000-01-01

    Paracoccidioidomycosis, a systemic mycosis restricted to Latin America and produced by the dimorphic fungus Paracoccidioides brasiliensis, is probably acquired by inhalation of conidia produced by the mycelial form. The macrophage (Mφ) represents the major cell defense against this pathogen; when activated with gamma interferon (IFN-γ), murine Mφs kill the fungus by an oxygen-independent mechanism. Our goal was to determine the role of nitric oxide in the fungicidal effect of Mφs on P. brasiliensis conidia. The results revealed that IFN-γ-activated murine Mφs inhibited the conidium-to-yeast transformation process in a dose-dependent manner; maximal inhibition was observed in Mφs activated with 50 U/ml and incubated for 96 h at 37°C. When Mφs were activated with 150 to 200 U of cytokine per ml, the number of CFU was 70% lower than in nonactivated controls, indicating that there was a fungicidal effect. The inhibitory effect was reversed by the addition of anti-IFN-γ monoclonal antibodies. Activation by IFN-γ also enhanced Mφ nitric oxide production, as revealed by increasing NO2 values (8 ± 3 μM in nonactivated Mφs versus 43 ± 13 μM in activated Mφs). The neutralization of IFN-γ also reversed nitric oxide production at basal levels (8 ± 5 μM). Additionally, we found that there was a significant inverse correlation (r = −0.8975) between NO2− concentration and transformation of P. brasiliensis conidia. Additionally, treatment with any of the three different nitric oxide inhibitors used (arginase, NG-monomethyl-l-arginine, and aminoguanidine), reverted the inhibition of the transformation process with 40 to 70% of intracellular yeast and significantly reduced nitric oxide production. These results show that IFN-γ-activated murine Mφs kill P. brasiliensis conidia through the l-arginine–nitric oxide pathway. PMID:10768942

  1. Tailoring fungal morphology of Aspergillus niger MYA 135 by altering the hyphal morphology and the conidia adhesion capacity: biotechnological applications

    PubMed Central

    2013-01-01

    Current problems of filamentous fungi fermentations and their further successful developments as microbial cell factories are dependent on control fungal morphology. In this connection, this work explored new experimental procedures in order to quantitatively check the potential of some culture conditions to induce a determined fungal morphology by altering both hyphal morphology and conidia adhesion capacity. The capacity of environmental conditions to modify hyphal morphology was evaluated by examining the influence of some culture conditions on the cell wall lytic potential of Aspergillus niger MYA 135. The relative value of the cell wall lytic potential was determined by measuring a cell wall lytic enzyme activity such as the mycelium-bound β-N-acetyl-D-glucosaminidase (Mb-NAGase). On the other hand, the quantitative value of conidia adhesion was considered as an index of its aggregation capacity. Concerning microscopic morphology, a highly negative correlation between the hyphal growth unit length (lHGU) and the specific Mb-NAGase activity was found (r = -0.915, P < 0.001). In fact, the environment was able to induce highly branched mycelia only under those culture conditions compatible with specific Mb-NAGase values equal to or higher than 190 U gdry.wt-1. Concerning macroscopic morphology, a low conidia adhesion capacity was followed by a dispersed mycelial growth. In fact, this study showed that conidia adhesion units per ml equal to or higher than 0.50 were necessary to afford pellets formation. In addition, it was also observed that once the pellet was formed the lHGU had an important influence on its final diameter. Finally, the biotechnological significance of such results was discussed as well. PMID:23688037

  2. A proteomic and genetic analysis of the Neurospora crassa conidia cell wall proteins identifies two glycosyl hydrolases involved in cell wall remodeling.

    PubMed

    Ao, Jie; Aldabbous, Mash'el; Notaro, Marysa J; Lojacono, Mark; Free, Stephen J

    2016-09-01

    A proteomic analysis of the conidial cell wall identified 35 cell wall proteins. A comparison with the proteome of the vegetative hyphae showed that 16 cell wall proteins were shared, and that these shared cell wall proteins were cell wall biosynthetic proteins or cell wall structural proteins. Deletion mutants for 34 of the genes were analyzed for phenotypes indicative of conidial cell wall defects. Mutants for two cell wall glycosyl hydrolases, the CGL-1 β-1,3-glucanase (NCU07523) and the NAG-1 exochitinase (NCU10852), were found to have a conidial separation phenotype. These two enzymes function in remodeling the cell wall between adjacent conidia to facilitate conidia formation and dissemination. Using promoter::RFP and promoter::GFP constructs, we demonstrated that the promoters for 15 of the conidia-specific cell wall genes, including cgl-1 and nag-1, provided for conidia-specific gene expression or for a significant increase in their expression during conidiation. PMID:27381444

  3. Modulation of conidia production and expression of the gene bbrgs1 from Beauveria bassiana by oxygen pulses and light.

    PubMed

    Rodriguez-Gomez, Divanery; Marcial-Quino, Jaime; Loera, Octavio

    2015-09-01

    Light and oxidant states affect the conidiation in diverse fungi, although the response has not been described when both stimuli are applied simultaneously. Conidial production and quality in Beauveria bassiana were analysed under four conditions for a wild-type (wt) strain and a previously isolated mutant (mt): normal atmosphere (21% O2; NA) or oxygen-enriched pulses (26% O2; OEP), with either light (L) or darkness (D). The response was complemented by following the expression of the bbrgs1 gene, encoding a regulator of the G-protein signal associated to conidia production. Conidiation was not significantly affected in the mutant strain by any condition (highest value with NA-L: 2.7×10(8)concm(-2)). Relative to maximal levels under NA (NA-D: 4×10(7)concm(2)), the wt strain diminished conidiation by 34-fold under OEP. The expression of bbrgs1 was higher (up to 188 times) in the mutant strain in every condition relative to the wt strain, in fact expression levels were consistent with the conidiation yields between strains. Viability and hydrophobicity were less affected by culture conditions, although pathogenicity parameters improved in conidia from OEP. The response to OEP, either with light or darkness, was strain-dependent for conidial production, viability, hydrophobicity and infectivity of conidia, then these parameters could be modulated in mass production processes. PMID:26166809

  4. The pbrB Gene Encodes a Laccase Required for DHN-Melanin Synthesis in Conidia of Talaromyces (Penicillium) marneffei

    PubMed Central

    Sapmak, Ariya; Boyce, Kylie J.; Andrianopoulos, Alex; Vanittanakom, Nongnuch

    2015-01-01

    Talaromyces marneffei (Basionym: Penicillium marneffei) is a significant opportunistic fungal pathogen in patients infected with human immunodeficiency virus in Southeast Asia. T. marneffei cells have been shown to become melanized in vivo. Melanins are pigment biopolymers which act as a non-specific protectant against various stressors and which play an important role during virulence in fungi. The synthesis of the two most commonly found melanins in fungi, the eumelanin DOPA-melanin and the allomelanin DHN-melanin, requires the action of laccase enzymes. The T. marneffei genome encodes a number of laccases and this study describes the characterization of one of these, pbrB, during growth and development. A strain carrying a PbrB-GFP fusion shows that pbrB is expressed at high levels during asexual development (conidiation) but not in cells growing vegetatively. The pbrB gene is required for the synthesis of DHN-melanin in conidia and when deleted results in brown pigmented conidia, in contrast to the green conidia of the wild type. PMID:25866870

  5. Surface Structure Characterization of Aspergillus fumigatus Conidia Mutated in the Melanin Synthesis Pathway and Their Human Cellular Immune Response

    PubMed Central

    Bayry, Jagadeesh; Beaussart, Audrey; Dufrêne, Yves F.; Sharma, Meenu; Bansal, Kushagra; Kniemeyer, Olaf; Aimanianda, Vishukumar; Brakhage, Axel A.; Kaveri, Srini V.; Kwon-Chung, Kyung J.

    2014-01-01

    In Aspergillus fumigatus, the conidial surface contains dihydroxynaphthalene (DHN)-melanin. Six-clustered gene products have been identified that mediate sequential catalysis of DHN-melanin biosynthesis. Melanin thus produced is known to be a virulence factor, protecting the fungus from the host defense mechanisms. In the present study, individual deletion of the genes involved in the initial three steps of melanin biosynthesis resulted in an altered conidial surface with masked surface rodlet layer, leaky cell wall allowing the deposition of proteins on the cell surface and exposing the otherwise-masked cell wall polysaccharides at the surface. Melanin as such was immunologically inert; however, deletion mutant conidia with modified surfaces could activate human dendritic cells and the subsequent cytokine production in contrast to the wild-type conidia. Cell surface defects were rectified in the conidia mutated in downstream melanin biosynthetic pathway, and maximum immune inertness was observed upon synthesis of vermelone onward. These observations suggest that although melanin as such is an immunologically inert material, it confers virulence by facilitating proper formation of the A. fumigatus conidial surface. PMID:24818666

  6. Comparison between conidia and blastospores of Esteya vermicola, an endoparasitic fungus of the pinewood nematode, Bursaphelenchus xylophilus.

    PubMed

    Wang, Yun-Bo; Yang, Zhi-Hong; Yu, Jiao-Jiao; Zhang, Yong-An; Xue, Jian-Jie; Li, Zheng; Li, Jing-Jie; Wang, Chun-Yan; Wang, Zhen; Hou, Jin-Gang; Begum, Shahraz; Gu, Li-Juan; Lee, Mi-Ra; Sung, Chang-Keun

    2013-12-01

    Esteya vermicola, an endoparasitic fungus of Bursaphelenchus xylophilus, the pinewood nematode (PWN), exhibits great potential as a biological control agent against this nematode. E. vermicola produces blastospores in liquid media and aerial conidia on solid media. The agent was mass-produced using two kinds of culture media: S (50 % wheat bran and 50 % pine wood powder), L (0.5 g wheat bran and 0.5 g pinewood powder in 200 ml of potato dextrose broth), and two controls: SC (potato dextrose agar), LC (potato dextrose broth). Yields, multiple stress tolerance, storage life, new generation conidial number, and PWN mortality rates of the spores were measured in each of these four media and compared. The spore yields, new generation conidial number, and nematode mortality rates of blastospores were higher than those of conidia. Nevertheless, the conidia had a higher germination rate than the blastospores during the storage process and multiple stress treatments. Considering the number of spores surviving from the process of the storage and multiple stress treatments per unit of mass media, the blastospores from L survived most. Comprehensive analysis indicates that the L culture medium is the most optimal medium for mass production relatively. PMID:23918632

  7. Distributions of the growth rate of the germ tubes and germination time of Penicillium chrysogenum conidia depend on water activity.

    PubMed

    Judet, Daniela; Bensoussan, Maurice; Perrier-Cornet, Jean-Marie; Dantigny, Philippe

    2008-10-01

    The effects of water activities for sporulation (a(wsp)) and germination (a(wge)) on the distributions of the growth rate of the germ tubes (mu) and the germination time (t(G)) of Penicillium chrysogenum conidia were determined by monitoring the length of the same germ tubes throughout the experiments automatically. No relationship between the individual t(G)'s and mu's could be established. Irrespective of the water activity for germination, mu was greater and t(G) was less for conidia produced at 0.95a(wsp) than that at 0.99a(wsp). At 0.99 a(wge) the mean and the standard deviation of t(G) were smaller than those obtained at 0.95a(wge). At 0.99a(wge), normal distributions for mu and t(G) were exhibited, but not at 0.95a(wge). The cumulative frequencies were used to reconstruct the germination curves. Great differences in the percentage of spores capable of germination (P(G)) and in the mean germination times between conidia produced at 0.95a(wsp) and at 0.99a(wsp) were clearly exhibited at 0.95a(wge), thus demonstrating the paramount influence of sporulation conditions on germination kinetics. PMID:18721680

  8. Consecutive monitoring of lifelong production of conidia by individual conidiophores of Blumeria graminis f. sp. hordei on barley leaves by digital microscopic techniques with electrostatic micromanipulation.

    PubMed

    Moriura, Nobuyuki; Matsuda, Yoshinori; Oichi, Wataru; Nakashima, Shinya; Hirai, Tatsuo; Sameshima, Takeshi; Nonomura, Teruo; Kakutani, Koji; Kusakari, Shin-Ichi; Higashi, Katsuhide; Toyoda, Hideyoshi

    2006-01-01

    Conidial formation and secession by living conidiophores of Blumeria graminis f. sp. hordei on barley leaves were consecutively monitored using a high-fidelity digital microscopic technique combined with electrostatic micromanipulation to trap the released conidia. Conidial chains formed on conidiophores through a series of septum-mediated division and growth of generative cells. Apical conidial cells on the conidiophores were abstricted after the conidial chains developed ten conidial cells. The conidia were electrically conductive, and a positive charge was induced in the cells by a negatively polarized insulator probe (ebonite). The electrostatic force between the conidia and the insulator was used to attract the abstricted conidia from the conidiophores on leaves. This conidium movement from the targeted conidiophore to the rod was directly viewed under the digital microscope, and the length of the interval between conidial septation and secession, the total number of the conidia produced by a single conidiophore, and the modes of conidiogenesis were clarified. During the stage of conidial secession, the generative cells pushed new conidial cells upwards by repeated division and growth. The successive release of two apical conidia was synchronized with the successive septation and growth of a generative cell. The release ceased after 4-5 conidia were released without division and growth of the generative cell. Thus, the life of an individual conidiophore (from the erection of the conidiophore to the release of the final conidium) was shown to be 107 h and to produce an average of 33 conidia. To our knowledge, this is the first report on the direct estimation of life-long conidial production by a powdery mildew on host leaves. PMID:16378716

  9. Intact Cell/Spore Mass Spectrometry of Fusarium Macro Conidia for Fast Isolate and Species Differentiation

    NASA Astrophysics Data System (ADS)

    Dong, Hongjuan; Marchetti-Deschmann, Martina; Winkler, Wolfgang; Lohninger, Hans; Allmaier, Guenter

    The focus of this paper is the development of an approach called intact cell mass spectrometry (ICMS) or intact spore mass spectrometry (ISMS) based on the technique matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) for the rapid differentiation and identification of Fusarium species. Several parameters, which are known to affect the quality of IC mass spectra, have been investigated in detail by varying the MALDI matrix as well as the solvent system, in which the matrix has been dissolved, the solvent system for sample purification and the type of sample/MALDI matrix deposition technique. In the end characteristic as well as highly reproducible IC or IS mass spectra or peptide/protein fingerprints of three Fusarium species (F. cerealis, F. graminearum and F. poae) including 16 Fusarium isolates derived from different hosts and geographical locations have been obtained. Unscaled hierarchical cluster analysis based on ICMS data of eight selected Fusarium isolates of two species F. graminearum and F. poae revealed significant difference among the peptide/protein pattern of them. The results of the applied cluster analysis proved that, ICMS is a powerful approach for the rapid differentiation of Fusarium species. In addition, an on-target tryptic digestion was applied to Fusarium macro conidia spores to identify proteins using MALDI post source decay (PSD) fragment ion analysis. Two kinds of trypsin, namely bead-immobilized - to favor cleavage of surface-associated proteins - and non-immobilized trypsin were applied and compared. The results showed that the latter is more suitable for generating sequence tags by PSD fragment ion analysis.

  10. Dark Period Following UV-C Treatment Enhances Killing of Botrytis cinerea Conidia and Controls Gray Mold of Strawberries.

    PubMed

    Janisiewicz, Wojciech J; Takeda, Fumiomi; Glenn, D Michael; Camp, Mary J; Jurick, Wayne M

    2016-04-01

    Strawberries are available throughout the year either from production in the field or from high and low tunnel culture. Diversity of production conditions results in new challenges in controlling diseases before and after harvest. Fungicides have traditionally been used to control these diseases; however, their limitations necessitate a search for new approaches. We found that UV-C irradiation of Botrytis cinerea, a major pathogen of strawberry, can effectively kill this fungus if a dark period follows the treatment. The inclusion of a 4-h dark period resulted in almost complete kill of B. cinerea conidia on agar media at a dose of 12.36 J/m2. The UV-C dose did not cause a reduction in photosynthesis in strawberry leaves or discoloration of sepals, even after exposing plants repeatedly (twice a week) for 7 weeks. Although irradiation of dry conidia of B. cinerea with this dose resulted in some survival, the conidia were not infective and not able to cause decay even when inoculated onto a highly susceptible mature apple fruit. Irradiation of strawberry pollen at 12.36 J/m2 did not affect pollen germination, tube growth and length in vitro, or germination and tube growth in the style of hand-pollinated emasculated strawberry flowers. No negative effect of the UV-C treatment was observed on fruit yield and quality in high tunnel culture. In the fruit and flower petal inoculation tests, the UV-C treatment was highly effective in reducing fruit decay and petal infection. This UV-C treatment with an exposure time of 60 s may be useful in controlling gray mold in tunnel production of strawberries and may also have the potential for use in intensive field and indoor production of other fruits and vegetables providing that a 4-h dark period follows the irradiation. PMID:26714103

  11. Taxonomy, nomenclature and phylogeny of three cladosporium-like hyphomycetes, Sorocybe resinae, Seifertia azaleae and the Hormoconis anamorph of Amorphotheca resinae

    PubMed Central

    Seifert, K.A.; Hughes, S.J.; Boulay, H.; Louis-Seize, G.

    2007-01-01

    Using morphological characters, cultural characters, large subunit and internal transcribed spacer rDNA (ITS) sequences, and provisions of the International Code of Botanical Nomenclature, this paper attempts to resolve the taxonomic and nomenclatural confusion surrounding three species of cladosporium-like hyphomycetes. The type specimen of Hormodendrum resinae, the basis for the use of the epithet resinae for the creosote fungus {either as Hormoconis resinae or Cladosporium resinae) represents the mononematous synanamorph of the synnematous, resinicolous fungus Sorocybe resinae. The phylogenetic relationships of the creosote fungus, which is the anamorph of Amorphotheca resinae, are with the family Myxotrichaceae, whereas S. resinae is related to Capronia (Chaetothyriales, Herpotrichiellaceae). Our data support the segregation of Pycnostysanus azaleae, the cause of bud blast of rhododendrons, in the recently described anamorph genus Seifertia, distinct from Sorocybe; this species is related to the Dothideomycetes but its exact phylogenetic placement is uncertain. To formally stabilize the name of the anamorph of the creosote fungus, conservation of Hormodendrum resinae with a new holotype should be considered. The paraphyly of the family Myxotrichaceae with the Amorphothecaceae suggested by ITS sequences should be confirmed with additional genes. PMID:18491002

  12. Binding of pulmonary surfactant proteins A and D to Aspergillus fumigatus conidia enhances phagocytosis and killing by human neutrophils and alveolar macrophages.

    PubMed Central

    Madan, T; Eggleton, P; Kishore, U; Strong, P; Aggrawal, S S; Sarma, P U; Reid, K B

    1997-01-01

    To determine whether the lung surfactant proteins A (SP-A) and D (SP-D) are involved in the initial protective immunity against opportunistic pulmonary fungal infections caused by Aspergillus fumigatus, we performed a series of in vitro functional studies to see if SP-A and SP-D enhanced binding, phagocytosis, activation, and killing of A. fumigatus conidia by human alveolar macrophages and circulating neutrophils. Both SP-A and SP-D bound to carbohydrate structures on A. fumigatus conidia in a calcium-dependent manner. SP-A and SP-D were also chemoattractant and significantly enhanced agglutination and binding of conidia to alveolar macrophages and neutrophils. Furthermore, in the presence of SP-A and SP-D, the phagocytosis, oxidative burst, and killing of A. fumigatus conidia by neutrophils were significantly increased. These findings indicate that SP-A and SP-D may have an important immunological role in the early antifungal defense responses in the lung, through inhibiting infectivity of conidia by agglutination and by enhancing uptake and killing of A. fumigatus by phagocytic cells. PMID:9234771

  13. Verruculogen associated with Aspergillus fumigatus hyphae and conidia modifies the electrophysiological properties of human nasal epithelial cells

    PubMed Central

    Khoufache, Khaled; Puel, Olivier; Loiseau, Nicolas; Delaforge, Marcel; Rivollet, Danièle; Coste, André; Cordonnier, Catherine; Escudier, Estelle; Botterel, Françoise; Bretagne, Stéphane

    2007-01-01

    Background The role of Aspergillus fumigatus mycotoxins in the colonization of the respiratory tract by conidia has not been studied extensively, even though patients at risk from invasive aspergillosis frequently exhibit respiratory epithelium damage. In a previous study, we found that filtrates of A. fumigatus cultures can specifically alter the electrophysiological properties of human nasal epithelial cells (HNEC) compared to those of non pathogenic moulds. Results We fractionated the organic phase of filtrate from 3-day old A. fumigatus cultures using high-performance liquid chromatography. The different fractions were tested for their ability to modify the electrophysiological properties of HNEC in an in vitro primary culture model. The fraction collected between 20 and 30 min mimicked the effects of the whole filtrate, i.e. decrease of transepithelial resistance and increase of potential differences, and contained secondary metabolites such as helvolic acid, fumagillin, and verruculogen. Only verruculogen (10-8 M) had effects similar to the whole filtrate. We verified that verruculogen was produced by a collection of 67 human, animal, plant and environmental A. fumigatus isolates. Using MS-MS analysis, we found that verruculogen was associated with both mycelium and conidia extracts. Conclusion Verruculogen is a secondary metabolite that modifies the electrophysiological properties of HNEC. The role of these modifications in the colonization and invasion of the respiratory epithelium by A. fumigatus on first contact with the epithelium remains to be determined. PMID:17244350

  14. Conidia immobilization of T-DNA inserted Trichoderma atroviride mutant AMT-28 with dichlorvos degradation ability and exploration of biodegradation mechanism.

    PubMed

    Sun, Wenliang; Chen, Yunpeng; Liu, Lixing; Tang, Jun; Chen, Jie; Liu, Peng

    2010-12-01

    An immobilizing conidia approach was used to study the degradation ability of dichlorvos in Trichoderma atroviride T-DNA insertional mutant AMT-28. Beads with 10(7) immobilized conidia per 100 mL of Na-alginate solution exhibited the highest degradation abilities. The immobilized conidia showed enhanced degradation abilities compared with immobilized or freely suspended mycelia. The immobilized cells kept good storage capacity and reusability. Dichlorvos was confirmed to be completely removed by mycelia of AMT-28 within 7 days using HPLC analysis. The dichlorvos degradation rates in auxotrophic Burk media varied and were significantly affected by nitrogen sources. There was no detectable biosorption and the removal of dichlorvos in AMT-28 was primarily attributed to a kind of Biomineralization process. PMID:20685111

  15. Field trials using the fungal pathogen, Metarhizium anisopliae (Deuteromycetes: Hyphomycetes) to control the ectoparasitic mite, Varroa destructor (Acari: Varroidae) in honey bee, Apis mellifera (Hymenoptera: Apidae) colonies.

    PubMed

    Kanga, Lambert Houssou Ble; Jones, Walker A; James, Rosalind R

    2003-08-01

    The potential for Metarhizium anisopliae (Metschinkoff) to control the parasitic mite, Varroa destructor (Anderson and Trueman) in honey bee colonies was evaluated in field trials against the miticide, tau-fluvalinate (Apistan). Peak mortality of V. destructor occurred 3-4 d after the conidia were applied; however, the mites were still infected 42 d posttreatments. Two application methods were tested: dusts and strips coated with the fungal conidia, and both methods resulted in successful control of mite populations. The fungal treatments were as effective as the Apistan, at the end of the 42-d period of the experiment. The data suggested that optimum mite control could be achieved when no brood is being produced, or when brood production is low, such as in the early spring or late fall. M. anisopliae was harmless to the honey bees (adult bees, or brood) and colony development was not affected. Mite mortality was highly correlated with mycosis in dead mites collected from sticky traps, indicating that the fungus was infecting and killing the mites. Because workers and drones drift between hives, the adult bees were able to spread the fungus between honey bee colonies in the apiary, a situation that could be beneficial to beekeepers. PMID:14503579

  16. Copulation Activity, Sperm Production and Conidia Transfer in Aedes aegypti Males Contaminated by Metarhizium anisopliae: A Biological Control Prospect

    PubMed Central

    Russell, Tanya L.; Braks, Marieta A. H.

    2015-01-01

    Background Dengue is the most prevalent arboviral disease transmitted by Aedes aegypti worldwide, whose chemical control is difficult, expensive, and of inconsistent efficacy. Releases of Metarhizium anisopliae—exposed Ae. aegypti males to disseminate conidia among female mosquitoes by mating represents a promising biological control approach against this important vector. A better understanding of fungus virulence and impact on reproductive parameters of Ae. aegypti, is need before testing auto-dissemination strategies. Methodology/Principal Findings Mortality, mating competitiveness, sperm production, and the capacity to auto-disseminate the fungus to females up to the 5thcopulation, were compared between Aedes aegypti males exposed to 5.96 x 107 conidia per cm2 of M. anisopliae and uninfected males. Half (50%) of fungus-exposed males (FEMs) died within the first 4 days post-exposure (PE). FEMs required 34% more time to successively copulate with 5 females (165 ± 3 minutes) than uninfected males (109 ± 3 minutes). Additionally, fungus infection reduced the sperm production by 87% at 5 days PE. Some beneficial impacts were observed, FEMs were able to successfully compete with uninfected males in cages, inseminating an equivalent number of females (about 25%). Under semi-field conditions, the ability of FEMs to search for and inseminate females was also equivalent to uninfected males (both inseminating about 40% females); but for the remaining females that were not inseminated, evidence of tarsal contact (transfer of fluorescent dust) was significantly greater in FEMs compared to controls. The estimated conidia load of a female exposed on the 5th copulation was 5,200 mL-1 which was sufficient to cause mortality. Conclusion/Significance Our study is the first to demonstrate auto-dissemination of M. anisopliae through transfer of fungus from males to female Ae. aegypti during mating under semi-field conditions. Our results suggest that auto-dissemination studies

  17. Activity of oil-formulated conidia of the fungal entomopathogens Nomuraea rileyi and Isaria tenuipes against lepidopterous larvae.

    PubMed

    Vega-Aquino, Paulina; Sanchez-Peña, Sergio; Blanco, Carlos A

    2010-03-01

    The fungi Nomuraea rileyi and Isaria tenuipes (=Paecilomyces tenuipes) are ecologically obligate, widespread pathogens of lepidopterans. Bioassays were carried out to evaluate the activity of oil-suspended conidia of N. rileyi and I. tenuipes against larvae of Spodoptera frugiperda, Spodoptera exigua, Helicoverpa zea, and Heliothis virescens. The tests consisted of two bioassay sets. In the first set, conidia of N. rileyi and I. tenuipes were suspended in water+Tween 80, and in vegetable (canola, soybean) and mineral (proprietary mixture of alkanes and cyclic paraffins) oils, and tested against S. frugiperda. Both fungi were highly compatible with oils and caused mortalities near 100% in all oil treatments; the lowest LT(50) values were 4.7 days for N. rileyi in mineral oil and 6.0 days for I. tenuipes in soybean oil. The second set included additional fungal strains and oil formulations (mineral, canola, sunflower, olive and peanut oils) tested against larvae of S. exigua, S. frugiperda, H. zea and H. virescens. The highest activity was that of N. rileyi in mineral oil against Spodoptera spp., with LT(50) values of 2.5 days (strain ARSEF 135) and 3 days (strain ARSEF 762) respectively. For two different isolates of I. tenuipes the lowest LT(50) values (5.1-5.6 days respectively) were obtained with mineral oil formulations against Spodoptera spp. and H. zea respectively. Additionally, we tested both fungi against prepupae of all four lepidopteran species. Mortalities with I. tenuipes against S. exigua ranged from 90% to 100% (strains ARSEF 2488 and 4096); N. rileyi caused 95% mortality on S. frugiperda. The activity of formulations depended on host species and oil used; Spodoptera spp. was more susceptible to these fungi than Heliothis and Helicoverpa. The results indicate that a comprehensive evaluation of these entomopathogens in agriculture using oil application technologies is advisable, particularly, in organic and sustainable settings. PMID:20025883

  18. Interactions of Chemical Additives, pH, and Temperature on Conidia Germination and Virulence of Colletotrichum truncatum, a Bioherbicide of Sesbania exaltata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We studied several factors that influence conidial germination and pathogenicity of the fungus Colletotrichum truncatum, which is a potential bioherbicide for hemp sesbania. The conidia germinated on 2% water agar over the pH range of 3.5 to 9.0, and the optimal pH for germination depended upon the ...

  19. Application of hydrophilic-lypophilic balance (HLB) number to optimize a compatible non-ionic surfactant for dried aerial conidia of Beauveria bassiana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The hydrophilic-lipophilic balance (HLB) number system was used to optimize a compatible non-ionic surfactant, TDA(polyoxyethylene tridecyl ether) in formulations for two Beauveria bassiana strains, NI8 and GHA. The optimal HLB number for TDA was determined on the basis of wetting times for conidia...

  20. Identification of a hard surface contact-induced gene in Colletotrichum gloeosporioides conidia as a sterol glycosyl transferase, a novel fungal virulence factor.

    PubMed

    Kim, Yeon-Ki; Wang, Yuhuan; Liu, Zhi-Mei; Kolattukudy, Pappachan E

    2002-04-01

    Hard surface contact has been known to be necessary to induce infection structure (appressorium) formation in many phytopathogenic fungi. However, the molecular basis of this requirement is unknown. We have used a differential display approach to clone some of the genes induced in the conidia by hard surface contact. We report that one of the genes induced by hard-surface contact of the conidia of Colletotrichum gloeosporioides, chip6, encodes a protein with homology to sterol glycosyl transferases. chip6 expressed in E. coli catalyses glucosyl transfer from UDP-glucose to cholesterol. Disruption of chip6 causes a marked decrease in the transferase activity and a drastic reduction in virulence on its natural host, avocado fruits, although the mutant is capable of normal growth and appressorium formation. The requirement for sterol glycosyl transferase for pathogenicity suggests a novel biological function for this transferase. PMID:12000454

  1. Aspergillus flavus Conidia-derived Carbon/Sulfur Composite as a Cathode Material for High Performance Lithium-Sulfur Battery

    NASA Astrophysics Data System (ADS)

    Xu, Maowen; Jia, Min; Mao, Cuiping; Liu, Sangui; Bao, Shujuan; Jiang, Jian; Liu, Yang; Lu, Zhisong

    2016-01-01

    A novel approach was developed to prepare porous carbon materials with an extremely high surface area of 2459.6 m2g-1 by using Aspergillus flavus conidia as precursors. The porous carbon serves as a superior cathode material to anchor sulfur due to its uniform and tortuous morphology, enabling high capacity and good cycle lifetime in lithium sulfur-batteries. Under a current rate of 0.2 C, the carbon-sulfur composites with 56.7 wt% sulfur loading deliver an initial capacity of 1625 mAh g-1, which is almost equal to the theoretical capacity of sulfur. The good performance may be ascribed to excellent electronic networks constructed by the high-surface-area carbon species. Moreover, the semi-closed architecture of derived carbons can effectively retard the polysulfides dissolution during charge/discharge, resulting in a capacity of 940 mAh g-1 after 120 charge/discharge cycles.

  2. Aspergillus flavus Conidia-derived Carbon/Sulfur Composite as a Cathode Material for High Performance Lithium-Sulfur Battery.

    PubMed

    Xu, Maowen; Jia, Min; Mao, Cuiping; Liu, Sangui; Bao, Shujuan; Jiang, Jian; Liu, Yang; Lu, Zhisong

    2016-01-01

    A novel approach was developed to prepare porous carbon materials with an extremely high surface area of 2459.6 m(2)g(-1) by using Aspergillus flavus conidia as precursors. The porous carbon serves as a superior cathode material to anchor sulfur due to its uniform and tortuous morphology, enabling high capacity and good cycle lifetime in lithium sulfur-batteries. Under a current rate of 0.2 C, the carbon-sulfur composites with 56.7 wt% sulfur loading deliver an initial capacity of 1625 mAh g(-1), which is almost equal to the theoretical capacity of sulfur. The good performance may be ascribed to excellent electronic networks constructed by the high-surface-area carbon species. Moreover, the semi-closed architecture of derived carbons can effectively retard the polysulfides dissolution during charge/discharge, resulting in a capacity of 940 mAh g(-1) after 120 charge/discharge cycles. PMID:26732547

  3. Growth of Esteya vermicola in media amended with nitrogen sources yields conidia with increased predacity and resistance to environmental stress.

    PubMed

    Wang, Zhen; Wang, Chun Yan; Gu, Li Juan; Wang, Yun Bo; Zhang, Yong An; Sung, Chang Keun

    2011-10-01

    Esteya vermicola , an endoparasitic fungus of pinewood nematode, exhibits great potential as a biological agent against nematodes. In this study to enhance the sporulation, predacity, and environmental resistance of E. vermicola, various nitrogen sources, such as glycine, L-leucine, and ammonium nitrate, were tested. The supplement of glycine and L-leucine had a significant influence on the growth rate of the colony, enhancing colony dry mass by 5-fold more than did ammonium nitrate or the control. Of the nitrogen sources tested, ammonium nitrate and L-leucine promoted sporulation, yielding more than 6 × 10(6) CFU/g, while glycine enhanced the proportion of lunate spores. Meanwhile, the supplement of nitrogen sources had a significant influence on adhesive rate and mortality rate against Bursaphelenchus xylophilus . Moreover, the supplement of glycine enhanced the survival rate against heat stress by more than 3-fold that of L-leucine, ammonium nitrate, and control. The spores produced in media amended with glycine, L-leucine, and ammonium nitrate had slightly but not significantly higher UV resistance and drought resistance than spores produced without nitrogen sources. These results suggested that the addition of glycine resulted in the production of E. vermicola conidia with increased predacity and resistance to environmental stress that may be more suitable for control of pine wilt disease. PMID:21942397

  4. Aspergillus flavus Conidia-derived Carbon/Sulfur Composite as a Cathode Material for High Performance Lithium–Sulfur Battery

    PubMed Central

    Xu, Maowen; Jia, Min; Mao, Cuiping; Liu, Sangui; Bao, Shujuan; Jiang, Jian; Liu, Yang; Lu, Zhisong

    2016-01-01

    A novel approach was developed to prepare porous carbon materials with an extremely high surface area of 2459.6 m2g−1 by using Aspergillus flavus conidia as precursors. The porous carbon serves as a superior cathode material to anchor sulfur due to its uniform and tortuous morphology, enabling high capacity and good cycle lifetime in lithium sulfur-batteries. Under a current rate of 0.2 C, the carbon-sulfur composites with 56.7 wt% sulfur loading deliver an initial capacity of 1625 mAh g−1, which is almost equal to the theoretical capacity of sulfur. The good performance may be ascribed to excellent electronic networks constructed by the high-surface-area carbon species. Moreover, the semi-closed architecture of derived carbons can effectively retard the polysulfides dissolution during charge/discharge, resulting in a capacity of 940 mAh g−1 after 120 charge/discharge cycles. PMID:26732547

  5. Survival of Penicillium spp. conidia during deep-frying and baking steps of frozen chicken nuggets processing.

    PubMed

    Wigmann, Évelin Francine; Moreira, Rafael Chelala; Alvarenga, Verônica Ortiz; Sant'Ana, Anderson S; Copetti, Marina Venturini

    2016-05-01

    This study aimed at determining whether Penicillium spp. strains could survive through the heat treatment applied during the processing of frozen chicken nuggets. Firstly, it was found that the conidia of Penicillium were not able to survive the heat shock in phosphate buffer at pH 7.2 in thermal death tubes (TDT) at 80 °C/30 min. Subsequently, each Penicillium strain was inoculated in frozen chicken nuggets, which were subjected to the following treatments: i) only deep frying (frying oil at 195-200 °C), ii) only baking (120-130 °C until the internal temperature reached 70 °C) and iii) deep frying followed by baking (frying oil temperature of 195-200 °C and baking temperature of 120-130 °C, until the internal temperature reached 70 °C). The results indicated that Penicillium polonicum NGT 23/12, Penicillium commune NGT 16/12, Penicillium solitum NGT 30/12 and Penicillium crustosum NGT 51/12 were able to survive after the combined treatment (deep frying followed by baking) when inoculated in chicken nuggets. P. polonicum NGT 23/12 was the most resistant strain to the combined treatment (deep frying and baking), as its population was reduced by 3 log cycles CFU/g, when the internal temperature reached 78 °C after 10 min and 30 s of baking. The present data show that if Penicillium spp. is present in high numbers in raw materials, such as breading flours, it will survive the thermal processing applied during chicken nuggets production. PMID:26742610

  6. Immunomodulatory effect of mesenchymal stem cells on the immune response of macrophages stimulated by Aspergillus fumigatus conidia.

    PubMed

    Cho, Sung-Yeon; Kwon, Eun-Young; Choi, Su-Mi; Lee, Dong-Gun; Park, Chulmin; Park, Sun Hee; Yoo, Jin-Hong; Choi, Jung-Hyun

    2016-05-01

    Mesenchymal stem cells (MSCs) are known to exert potent immunosuppression and anti-inflammatory effects. There is growing interest in their use for immunotherapy for controlling inflammation as well as acute organ injury. However, there are few reports regarding MSC's immunomodulatory effects in the settings of fungal infection. In this study, we attempted to examine the immunomodulatory effects of MSCs in response toAspergillus fumigatus We measured the cytokine response of murine MSCs on the immune response of murine macrophages (J774A.1 cells) evoked byA. fumigatusconidia. In addition, we evaluated the effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on the MSC-related cytokine response and fungal growth. As a results, after conidia stimulation, tumor necrosis factor (TNF)-α was down-regulated and interleukin (IL)-10 was up-regulated in MSC-treated J774A.1 cells when compared to J774A.1 cells alone. In addition, fungal growth was reduced in MSC-treated J774A.1 cells when compared to J774A.1 cells, which recovered by GM-CSF. However, the effect of MSCs on the cytokine response was not reversed by GM-CSF. NF-κB translocation decreased in MSC-treated J774A.1 cells compared to J774A.1 cells alone. In conclusion, MSCs demonstrate immunomodulatory properties in both aspects of cytokines and fungal growth. The anti-inflammatory effect of MSCs with regard to cytokine response might be associated with decreased NF-κB translocation, and is not reversed by GM-CSF. PMID:26768375

  7. Effects of Airflow and Changing Humidity on the Aerosolization of Respirable Fungal Fragments and Conidia of Botrytis cinerea

    PubMed Central

    2012-01-01

    The purpose of this study was to investigate the aerosolization of particles (micro- and macroconidia and fragments) from Botrytis cinerea cultures in relation to potential human inhalation in indoor environments. The influence of the following factors on the aerosolization of B. cinerea particles was studied: exposure to airflow, relative humidity (rh), changing rh, and plant or building materials. The aerodynamic diameter (da) and the respirable fraction of the aerosolized particles were determined. Conidia and fragments of B. cinerea were not aerosolized as a response to a decrease in the rh. In contrast, both micro- and macroconidia and fungal fragments were aerosolized when exposed to an airflow of 1.5 m s−1 or 0.5 m s−1. Significantly more particles of microconidial size and fragment size were aerosolized at a low rh (18 to 40% rh) than at a higher rh (60 to 80% rh) when cultures were exposed to airflow. The size of the respirable fraction of the aerosolized particles was dependent on the rh but not on the growth material. At high rh, about 30% of the aerosolized particles were of respirable size, while at low rh, about 70% were of respirable size. During low rh, more fungal (1→3)-β-d-glucan and chitinase were aerosolized than during high rh. In conclusion, exposure to external physical forces such as airflow is necessary for the aerosolization of particles from B. cinerea. The amount and size distribution are highly affected by the rh, and more particles of respirable sizes were aerosolized at low rh than at high rh. PMID:22447608

  8. A few shared up-regulated genes may influence conidia to yeast transformation in dimorphic fungal pathogens.

    PubMed

    Kirkland, Theo N

    2016-08-01

    The small number of fungi that commonly cause disease in normal people share the capacity to grow as mycelia in the soil at 25°C and as yeast (or spherules) in mammals at 37°C. This remarkable conversion has long been a topic of interest in medical mycology. The conidia to yeast conversion has been studied by transcription profiling in several fungal species, including Histoplasma capsulatum, Paracoccidioides brasiliensis, Coccidioides spp., Blastomyces dermatitidis, and Talaromyces marneffei One limitation of transcriptional profiling is determining which genes are involved in the process of conversion to yeast as opposed to a result of conversion to yeast. If there are genes that are up-regulated in the yeast phase of more than one dimorphic, pathogenic fungus they might be required for conversion to yeast (or spherules). To address this issue, 24 up-regulated genes common to Coccidioides spp spherules and H. capsulatum yeasts were identified. Four homologs of these genes were also found in P. brasiliensis, B. dermatitidis or T. marneffei genes that were up-regulated in yeast. 4-hydroxyphenylpurvate dioxygenase, a gene involved in tyrosine metabolism and melanin synthesis that has been shown to be required for yeast conversion, is conserved and up-regulated in yeast in all five species. Another up-regulated gene that is conserved in all five species is a MFS sugar porter. These results suggest that a minority of up-regulated yeast (or spherule) genes are conserved across species and raises the possibility that conserved up-regulated genes may be of special interest for differentiation of mycelium into yeast. PMID:27118798

  9. Liquid culture production of microsclerotia and submerged conidia by Trichoderma harzianum active against damping-off disease caused by Rhizoctonia solani.

    PubMed

    Kobori, Nilce N; Mascarin, Gabriel M; Jackson, Mark A; Schisler, David A

    2015-04-01

    Media and culturing protocols were identified that supported the formation of submerged conidia and microsclerotia (MS) by Trichoderma harzianum Rifai strain T-22 using liquid culture fermentation. Liquid media with a higher carbon concentration (36 g L(-1)) promoted MS formation at all C:N ratios tested. Hyphae aggregated to form MS after 2 d growth and after 7 d MS were fully melanized. This is the first report of MS formation by T. harzianum or any species of Trichoderma. Furthermore, submerged conidia formation was induced by liquid culture media, but yields, desiccation tolerance, and storage stability varied with C:N ratio and carbon rate. Air-dried MS granules (<4% moisture) retained excellent shelf life under cool and unrefrigerated storage conditions with no loss in conidial production. A low-cost complex nitrogen source based on cottonseed flour effectively supported high MS yields. Amending potting mix with dried MS formulations reduced or eliminated damping-off of melon seedlings caused by Rhizoctonia solani. Together, the results provide insights into the liquid culture production, stabilization process, and bioefficacy of the hitherto unreported MS of T. harzianum as a potential biofungicide for use in integrated management programs against soilborne diseases. PMID:25813507

  10. A comparison between intratracheal and inhalation delivery of Aspergillus fumigatus conidia in the development of fungal allergic asthma in C57BL/6 mice

    PubMed Central

    Samarasinghe, Amali E.; Hoselton, Scott A.; Schuh, Jane M.

    2010-01-01

    Summary Allergic asthma is a debilitating disease of the airways characterized by airway hyperresponsiveness, eosinophilic inflammation, goblet cell metaplasia with associated mucus hypersecretion, and airway wall remodelling events, particularly subepithelial fibrosis and smooth muscle cell hyperplasia. Animal models that accurately mimic these hallmarks of allergic airways disease are critical for studying mechanisms associated with the cellular and structural changes that lead to disease pathogenesis. Aspergillus fumigatus, is a common aeroallergen of human asthmatics. The intratracheal (IT) delivery of A. fumigatus conidia into the airways of sensitized mice has been described as a model of allergic disease. Here, we compared the IT model with a newly developed inhalation (IH) challenge model. The IH model allowed multiple fungal exposures, which resulted in an exacerbation to the allergic asthma phenotype. Increased recruitment of eosinophils and lymphocytes, the hallmark leukocytes of asthma, were noted with the IH model as compared to the IT model in which macrophages and neutrophils were more prominent. Immunoglobulin E (IgE) production was significantly greater after IH challenge, while that of IgG2a was higher after IT challenge. Airway wall remodelling was pronounced in IH-treated mice, particularly after multiple allergen challenges. Although the IT model may be appropriate for the examination of the played by innate cells in the acute response to fungus, it fails to consistently reproduce the chronic remodelling hallmarks of allergic asthma. The ability of the IH challenge to mimic these characteristics recommends it as a model suited to study these important events. PMID:21215951

  11. A comparison between intratracheal and inhalation delivery of Aspergillus fumigatus conidia in the development of fungal allergic asthma in C57BL/6 mice.

    PubMed

    Samarasinghe, Amali E; Hoselton, Scott A; Schuh, Jane M

    2011-01-01

    Allergic asthma is a debilitating disease of the airways characterized by airway hyperresponsiveness, eosinophilic inflammation, goblet cell metaplasia with associated mucus hypersecretion, and airway wall remodelling events, particularly subepithelial fibrosis and smooth muscle cell hyperplasia. Animal models that accurately mimic these hallmarks of allergic airways disease are critical for studying mechanisms associated with the cellular and structural changes that lead to disease pathogenesis. Aspergillus fumigatus, is a common aeroallergen of human asthmatics. The intratracheal (IT) delivery of A. fumigatus conidia into the airways of sensitized mice has been described as a model of allergic disease. Here, we compared the IT model with a newly developed inhalation (IH) challenge model. The IH model allowed multiple fungal exposures, which resulted in an exacerbation to the allergic asthma phenotype. Increased recruitment of eosinophils and lymphocytes, the hallmark leukocytes of asthma, was noted with the IH model as compared to the IT model in which macrophages and neutrophils were more prominent. Immunoglobulin E (IgE) production was significantly greater after IH challenge, while that of IgG(2a) was higher after IT challenge. Airway wall remodelling was pronounced in IH-treated mice, particularly after multiple allergen challenges. Although the IT model may be appropriate for the examination of the played by innate cells in the acute response to fungus, it fails to consistently reproduce the chronic remodelling hallmarks of allergic asthma. The ability of the IH challenge to mimic these characteristics recommends it as a model suited to study these important events. PMID:21215951

  12. Proteomic analysis of conidia germination in Fusarium oxysporum f. sp. cubense tropical race 4 reveals new targets in ergosterol biosynthesis pathway for controlling Fusarium wilt of banana.

    PubMed

    Deng, Gui-Ming; Yang, Qiao-Song; He, Wei-Di; Li, Chun-Yu; Yang, Jing; Zuo, Cun-Wu; Gao, Jie; Sheng, Ou; Lu, Shao-Yun; Zhang, Sheng; Yi, Gan-Jun

    2015-09-01

    Conidial germination is a crucial step of the soilborne fungus Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4), a most important lethal disease of banana. In this study, a total of 3659 proteins were identified by isobaric tags for relative and absolute quantitation (iTRAQ)-based comparative proteomic approach, of which 1009 were differentially expressed during conidial germination of the fungus at 0, 3, 7, and 11 h. Functional classification and bioinformatics analysis revealed that the majority of the differentially expressed proteins are involved in six metabolic pathways. Particularly, all differential proteins involved in the ergosterol biosynthesis pathway were significantly upregulated, indicating the importance of the ergosterol biosynthesis pathway to the conidial germination of Foc TR4. Quantitative RT-PCR, western blotting, and in vitro growth inhibition assay by several categories of fungicides on the Foc TR4 were used to validate the proteomics results. Four enzymes, C-24 sterol methyltransferase (ERG6), cytochrome P450 lanosterol C-14α-demethylase (EGR11), hydroxymethylglutaryl-CoA synthase (ERG13), and C-4 sterol methyl oxidase (ERG25), in the ergosterol biosynthesis pathway were identified and verified, and they hold great promise as new targets for effective inhibition of Foc TR4 early growth in controlling Fusarium wilt of banana. To the best of our knowledge, this report represents the first comprehensive study on proteomics profiling of conidia germination in Foc TR4. It provides new insights into a better understanding of the developmental processes of Foc TR4 spores. More importantly, by host plant-induced gene silencing (HIGS) technology, the new targets reported in this work allow us to develop novel transgenic banana leading to high protection from Fusarium wilt and to explore more effective antifungal drugs against either individual or multiple target proteins of Foc TR4. PMID:26129952

  13. Species and ecological diversity within the Cladosporium cladosporioides complex (Davidiellaceae, Capnodiales)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Cladosporium is one of the largest genera of dematiaceous hyphomycetes, and is characterised by a coronate scar structure, conidia in acropetal chains and Davidiella teleomorphs. Based on morphology and DNA phylogeny, the species complexes of C. herbarum and C. sphaerospermum have been res...

  14. SPM and fungal spores in the ambient air of west Korea during the Asian dust (Yellow sand) period

    NASA Astrophysics Data System (ADS)

    Yeo, Hwan-Goo; Kim, Jong-Ho

    The relationship between suspended particulate matter (SPM) and fungal spore was investigated in Seosan, a rural county along the west coast of Korea, in the spring of 2000. SPM concentrations in the air were 199.8 μg m -3 in the first Asian dust period (23-24 March), 249.4 μg m -3 in the second Asian dust period (7-9 April) and 98.9 μg m -3 in the non-Asian dust period (12-16 May), respectively. The majority of the total SPM were composed of coarse particles sized about 5 μm during the two Asian dust periods. Four molds genera grown from airborne fungal spores were identified in colonies grown from SPM samples taken during the Asian dust periods. All the genera found, Fusarium, Aspergillus, Penicillium and Basipetospora, are hyphomycetes in the division Deuteromycota. Morphologically, more diversified mycelia of hyphomycetes were grown on the sample captured from 1.1 to 2.1 μm sized SPM than on the other sized samples gathered in the dust periods. On the other hand, no mold was observed on the sample of 1.1-2.1 μm sized SPM in the non-Asian dust period. From these results, it seems evident that several sorts of fine sized fungal spores were suspended in the atmospheric environment of this study area during Asian dust periods.

  15. Transformation of Epichloë typhina by electroporation of conidia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Choke, caused by the endophytic fungus Epichloë typhina is an important disease of orchardgrass (Dactylis glomerata L.) grown for seed. Very little is known concerning the conditions necessary for successful infection of orchardgrass by E. typhina. Detection of E. typhina early in the disease cycle ...

  16. Reclassification of Cladosporium bantianum in the genus Xylohypha.

    PubMed Central

    McGinnis, M R; Borelli, D; Padhye, A A; Ajello, L

    1986-01-01

    It is proposed that the dematiaceous hyphomycete Cladosporium bantianum (Saccardo) Borelli be transferred to the genus Xylohypha (Fries) Mason as Xylohypha bantiana (Saccardo) McGinnis, Padhye, Borelli, et Ajello. This new combination is necessary because X. bantiana produces conidiophores that are indistinguishable from its vegetative hyphae and one-celled, smooth-walled conidia that are borne in long, infrequently branched chains. The blastoconidia do not possess darkly pigmented hila. In contrast, members of the genus Cladosporium Link produce erect, distinct conidiophores and one- to four-celled smooth-to-rough-walled conidia that occur in short, frequently branched, fragile chains. The blastoconidia have darkly pigmented hila. Cladosporium trichoides Emmons is a later synonym of X. bantiana. Images PMID:3711309

  17. In vitro and in planta compatibility of insecticides and the endophytic entomopathogen, Lecanicillium lecanii.

    PubMed

    Gurulingappa, Pampapathy; Mc Gee, Peter; Sword, Gregory A

    2011-08-01

    In an attempt to clarify the potential role of endophytic fungi in integrated pest management, the compatibility of an endophytic isolate of Lecanicillium lecanii (Zimmermann) Gams & Zare (Hyphomycetes) with nine insecticides used against Aphis gossypii Glover (Homoptera : Aphididae) was examined both in vitro over 14 days and in planta. In the laboratory, most insecticides partially or completely inhibited the germination of conidia and growth of hyphae in nutrient-rich conditions. Endosulfan completely inhibited the germination of conidia and hyphal growth. In contrast, all insecticides were compatible with L. lecanii in planta, and the fungus was readily recovered from inoculated, colonized leaves. These data support the hypothesis that endophytic L. lecanii will be unaffected by insecticides and could be integrated in the management of pests in cotton. PMID:21424605

  18. The role of antennae in removing entomopathogenic fungi from cuticle of the termite, Coptotermes formosanus.

    PubMed

    Yanagawa, Aya; Yokohari, Fumio; Shimizu, Susumu

    2009-01-01

    Our previous research has shown that the termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), protects itself from entomopathogenic fungi by mutual grooming behavior. The termite removes and discards foreign organisms, such as fungal conidia, from the body surface of its nestmates by mutual grooming behavior. The role of the antennae in detecting the condia was examind here. Three entomopathogenic fungi were used, Beauveria brongniartii 782 (Saccardo) (Hypocreales), Paecilomyces fumosoroseus K3 (Wize) (Hyphomycetes), and Metarhizium anisopliae 455 Sorokin (Hyphomycetes). Termites with antennae removed conidia more efficiently than termites without antennae. There were differences between termites with and without antennae in selection of sites to be groomed on nestmates, in the length of grooming and in occurrence of grooming. Electroantennogram (EAG) responses were recorded from termite antennae and the waveforms were rather specific to the kinds of fungi used as odor sources. Termites were able to distinguish between the tested fungi in feeding tests. These results show that the antennae play important roles in the mutual grooming behavior of the termite. PMID:19611249

  19. Biologically active polyketide metabolites from an undetermined fungicolous hyphomycete resembling Cladosporium.

    PubMed

    Höller, Ulrich; Gloer, James B; Wicklow, Donald T

    2002-06-01

    Eight new polyketide-derived metabolites [cladoacetals A and B (1 and 2), 3-(2-formyl-3-hydroxyphenyl)propionic acid (3), 3-deoxyisoochracinic acid (4), isoochracinol (5), 7-hydroxy-3-(2,3-dihydroxybutyl)-1(3H)-isobenzofuranone (6), (+)-cyclosordariolone (10), and altersolanol J (11)] and six known metabolites [two isomeric 1-(1,3-dihydro-4-hydroxy-1-isobenzofuranyl)butan-2,3-diols (7a/b), 7-hydroxy-1(3H)-isobenzofuranone (8), isoochracinic acid (9), altersolanol A (12), and macrosporin (13)] have been isolated from solid-substrate fermentation cultures of an undetermined fungicolous isolate (NRRL 29097) that resembles Cladosporium sp. All structures were assigned primarily by analysis of 1D and/or 2D NMR data. Five of the compounds showed antibacterial activity. PMID:12088431

  20. CELL-WALL DEGRADING ENZYMES OF AQUATIC HYPHOMYCETES: A REVIEW. (U915444)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  1. EFFICACY OF BEAUVERIA BASSIANA (HYPHOMYCETES) FOR CONTROL OF RUSSIAN WHEAT APHID (HOMOPTERA: APHIDAE) ON RESISTANT WHEAT UNDER FIELD CONDITION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The microbial control potential of the entomopathogenic fungus Beauveria bassiana was evaluated against Russian wheat aphid (RWA) infesting RWA-resistant wheat cultivars near Bethlehem, Free State Province, South Africa. In small-scale field trials using a back-pack hydraulic sprayer, a single appl...

  2. A century later: rediscovery, culturing and phylogenetic analysis of Diploöspora rosea, a rare onygenalean hyphomycete.

    PubMed

    Tanney, Joey B; Nguyen, Hai D T; Pinzari, Flavia; Seifert, Keith A

    2015-11-01

    Nearly 100 years after its first discovery, Diploöspora rosea was detected on biologically damaged parchment paper in Rome, Italy and isolated from house dust collected in Micronesia. The isolation of this culture permitted morphological study of colony characters, conidium and conidiophore development, and phylogenetic investigations using sequences of nuc 18S rDNA, internal transcribed spacers, and 28S rDNA. The results indicate that D. rosea is an onygenalean fungus, of uncertain taxonomic position, basal or sister to the Gymnoascaceae. Based on observations of the parchments using SEM-Energy Dispersive Spectroscopy, we speculate that the fungus occurs in archival and domestic environments subject to periodic wetting. Its ability to grow on all low water activity media used in the study, including malt extract agar amended with 60% sucrose, confirms its xerophilic nature. PMID:26363911

  3. Evaluation of disinfectants to control contamination of citrus degreening rooms with conidia, 2008

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early season oranges are harvested and treated with ethylene gas for two or more days in humidified ‘degreening’ rooms at 20C to accelerate the degradation of chlorophyll to enhance the orange color of the fruit rind. Decay of the fruit during this process by P. digitatum is common and between cycle...

  4. Preillumination of rice blast conidia induces tolerance to subsequent oxidative stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many environmental factors, alone or combined, affect organisms by changing a pro-/antioxidant balance. Here we tested rice blast fungus (Magnaporthe oryzae) for possible cross-adaptations caused by relatively intense light and protecting from artificially formed reactive oxygen species (ROS) and RO...

  5. Production of Macrophomina phaseolina conidia by multiple soybean isolates in culture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Macrophomina phaseolina (Tassi) Goid is the cause of charcoal rot of soybean, Glycine max (L.) (Merr.). Soybean resistance to M. phaseolina in commercial cultivars is not common, but is especially needed in locations where the disease is chronic and severe. The objective of this study was to develop...

  6. The allergenicity of Aspergillus fumigatus conidia is influenced by growth temperature.

    PubMed

    Low, Swee Yang; Dannemiller, Karen; Yao, Maosheng; Yamamoto, Naomichi; Peccia, Jordan

    2011-07-01

    Common indoor and outdoor environmental fungi such as Aspergillus fumigatus produce asexual spores containing a collection of proteins that can bind IgE antibodies and trigger allergic reactions. We characterized the impact of sporulation temperature on the IgE-binding capacity (allergenicity) of A. fumigatus and explored the links between variable allergenicity and temperature-dependant expression of genes encoding these allergenic proteins. A 12-fold increase in A. fumigatus allergenicity per spore was observed when sporulation temperatures were decreased from 32°C to 17°C. Per spore protein mass and Asp f 1 allergen mass also followed this trend. Functional gene expression analysis of A. fumigatus sporulating cultures by real-time reverse-transcription PCR and gene expression microarrays revealed that a greater number of genes encoding known, major allergens are more highly expressed at lower sporulation temperatures. The results of this study indicate that environmental conditions at growth significantly influence the allergenicity of this common mould through the differential production of allergenic proteins, and highlight the importance of in vivo or in vitro allergenicity measurements for understanding environmental exposure to airborne allergenic fungi. PMID:21724168

  7. Aerial dispersal and drying of Peronospora tabacina conidia in tobacco shade tents

    PubMed Central

    Aylor, Donald E.; Taylor, Gordon S.

    1982-01-01

    Blue mold of tobacco is caused by the fungus Peronospora tabacina. Its spores are released in the morning when the relative humidity falls, but they require free water for germination. Traditionally, the walls of the shade tents are raised to control the pathogen by drying leaves. We show that raising the walls does not materially speed drying. It does, however, increase the wind speed at least 20 m inside the tent and spread spores farther. Because germination is not reduced, raising the walls may actually spread blue mold. PMID:16593150

  8. Detection of Pyrenophora teres in conidia and barley seed by a rapid PCR technique

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pyrenophora teres, the causal agent of net blotch of barley survives as seedborne mycelium or pseudothesia in infested host residues. Besides the common netlike and occasional spot form symptoms on barley leaves, diffused dark or pale symptoms which are difficult to distinguish from other fungi are ...

  9. Confirming resistance in bottle gourd germplasm by quantifying powdery mildew conidia using a cellometer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Powdery mildew (PM) caused by Podosphaera xanthii, an important foliar disease affecting cucurbit crops grown in the United States, commonly occurs on foliage, petioles, and stems. We have developed two highly resistant bottle gourd (Lagenaria siceraria) germplasm (USVL351 and USVL482) for use in o...

  10. Pre-illumination of rice blast conidia induces tolerance to subsequent oxidative stress.

    PubMed

    Aver'yanov, Andrey A; Lapikova, Vera P; Pasechnik, Tatiana D; Abramova, Olga S; Gaivoronskaya, Ludmilla M; Kuznetsov, Vladimir V; Baker, C Jacyn

    2014-08-01

    Many environmental factors, alone or combined, affect organisms by changing a pro-/antioxidant balance. Here we tested rice blast fungus (Magnaporthe oryzae) for possible cross-adaptations caused by relatively intense light and protecting from artificially formed reactive oxygen species (ROS) and ROS-dependent fungitoxic response of the host plant. Spore germination was found to be suppressed under 4-h and, to larger extent, 5-h illumination. The effect was diminished by antioxidants and, therefore, suggests involvement of ROS. One-hour of light did not affect spore germination, but stimulated their chemically assayed superoxide production. The illuminated spores were more tolerant (than non-illuminated ones) to artificially generated H(2)O(2), O(2)(-), or OH or to toxic diffusate of rice leaf. They also caused more severe disease symptoms if applied to leaves of the susceptible rice cultivar at low concentration. Spore diffusates decomposed hydrogen peroxide. They detoxified exogenous H(2)O(2) and superoxide radical as well as leaf diffusates. Spore illumination increased some of these protective effects. It is suggested that short-term light led to mild oxidative stress, which induced spore antioxidant capacity, enhancing spore tolerance to subsequent stronger oxidative stress and its aggressiveness in planta. Such tolerance depends partly on the antidotal action of spore extracellular compounds, which may also be light-stimulated. Therefore, a certain ROS-related environmental factor may adapt a fungus to other factors and so modulate its pathogenic properties. PMID:25110136

  11. The potential role of water in spread of conidia of the Neotyphodium endophyte of Poa ampla

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Endophytes of the genus Neotyphodium are mutualistic fungi that colonize many cool season grasses. Neotyphodium endophytes are asexual but related to the ascomycete genus Epichloe. They do not produce obvious structures external to the host and for most of the life cycle are asymptomatic and system...

  12. Effect of storage temperature and sphacellum age on C. africana conidia survival

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sorghum ergot, caused by Claviceps africana Frederickson, Mantle & de Milliano, is a disease that poses a serious treat to sorghum, especially in hybrid seed production. The initial sign of the disease is called a sphacelium. Sphacelia containing macroconidia could play a role in the survival of t...

  13. Shelf-life of Beauveria bassiana conidia in gaseous atmospheres under high temperature regimes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The retention of high viability during storage is essential for effectiveness and thus market acceptance of fungus-based biopesticides. The length of adequate shelf-lives for mycoinsecticides is controversial, with proposed requirements varying from a few weeks to 18 months. Shelf-life determination...

  14. Commercial detergents effective against conidia and chlamydospores of Fusarium oxysporum f. sp. vasinfectum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current containment recommendations for limiting the spread of race 4 of Fusarium oxysporum f. sp. vasinfectum in California lack non-corrosive yet effective alternatives to bleach for sanitizing equipment used in farming operations. To find an equivalent to Farmcleanse, an Australian product recomm...

  15. Imbibitional damage in conidia of the entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, and Metarhizium acridum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When dried organisms are immersed in water, rapid imbibition may cause severe damage to plasma membranes; in unicellular organisms, such damage is usually lethal. This study investigated effects of pre-immersion moisture levels and immersion temperature on imbibitional damage in three insect pathoge...

  16. Beauveria bassiana, Metarhizium anisopliae, and Metarhizium anisopliae var. acridum conidia: tolerance to imbibitional damage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When dry fungal cells are immersed in water, rapid imbibition (water uptake) may compromise the plasma membrane, killing the cell. This study investigated the impact of imbibitional damage (measured in terms of reduced viability) on Beauveria bassiana (Bb), Metarhizium anisopliae (Ma) and M. anisop...

  17. Storage conditions affect speed of germination in Beauveria bassiana and Metarhizium anisopliae conidia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The retention of high viability during storage is essential for effectiveness and thus market acceptance of fungus-based biopesticides. The length of adequate shelf-lives for mycoinsecticides is controversial, with proposed requirements varying from a few weeks to 18 months. Shelf-life determination...

  18. Determining Diversity of Freshwater Fungi on Decaying Leaves: Comparison of Traditional and Molecular Approaches

    PubMed Central

    Nikolcheva, Liliya G.; Cockshutt, Amanda M.; Bärlocher, Felix

    2003-01-01

    Traditional microscope-based estimates of species richness of aquatic hyphomycetes depend upon the ability of the species in the community to sporulate. Molecular techniques which detect DNA from all stages of the life cycle could potentially circumvent the problems associated with traditional methods. Leaf disks from red maple, alder, linden, beech, and oak as well as birch wood sticks were submerged in a stream in southeastern Canada for 7, 14, and 28 days. Fungal biomass, estimated by the amount of ergosterol present, increased with time on all substrates. Alder, linden, and maple leaves were colonized earlier and accumulated the highest fungal biomass. Counts and identifications of released conidia suggested that fungal species richness increased, while community evenness decreased, with time (up to 11 species on day 28). Conidia of Articulospora tetracladia dominated. Modifications of two molecular methods—denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism (T-RFLP) analysis—suggested that both species richness and community evenness decreased with time. The dominant ribotype matched that of A. tetracladia. Species richness estimates based on DGGE were consistently higher than those based on T-RFLP analysis and exceeded those based on spore identification on days 7 and 14. Since traditional and molecular techniques assess different aspects of the fungal organism, both are essential for a balanced view of fungal succession on leaves decaying in streams. PMID:12732520

  19. Septoria-like pathogens causing leaf and fruit spot of pistachio.

    PubMed

    Crous, Pedro W; Quaedvlieg, William; Sarpkaya, Kamil; Can, Canan; Erkılıç, Ali

    2013-12-01

    Several species of Septoria are associated with leaf and fruit spot of pistachio (Pistacia vera), though their identity has always been confused, making identification problematic. The present study elucidates the taxonomy of the Septoria spp. associated with pistachio, and distinguishes four species associated with this host genus. Partial nucleotide sequence data for five gene loci, ITS, LSU, EF-1α, RPB2 and Btub were generated for a subset of isolates. Cylindroseptoria pistaciae, which is associated with leaf spots of Pistacia lentiscus in Spain, is characterised by pycnidial conidiomata that give rise to cylindrical, aseptate conidia. Two species of Septoria s. str. are also recognised on pistachio, S. pistaciarum, and S. pistaciae. The latter is part of the S. protearum species complex, and appears to be a wide host range pathogen occurring on hosts in several different plant families. Septoria pistacina, a major pathogen of pistachio in Turkey, is shown to belong to Pseudocercospora, and not Septoria as earlier suspected. Other than for its pycnidial conidiomata, it is a typical species of Pseudocercospora based on its smooth, pigmented conidiogenous cells and septate conidia. This phenomenon has also been observed in Pallidocercospora, and seriously questions the value of conidiomatal structure at generic level, which has traditionally been used to separate hyphomycetous from coelomycetous ascomycetes. Other than DNA barcodes to facilitate the molecular identification of these taxa occurring on pistachio, a key is also provided to distinguish species based on morphology. PMID:24563831

  20. Pseudosigmoidea ibarakiensis sp. nov., a Dark Septate Endophytic Fungus from a Cedar Forest in Ibaraki, Japan

    PubMed Central

    Diene, Ousmane; Wang, Wei; Narisawa, Kazuhiko

    2013-01-01

    A dark septate fungus of Pseudosigmoidea, Hyphomycetes, was recovered from forest soil in Ibaraki prefecture, Japan. The isolate is characterized by pale to brown conidia with up to 8 septa measuring 68–132 × 4–7.9 μm. It is also unique in producing conidia borne by long conidogenious cells in agar medium with or without water, compared to P. cranei, which must be immersed in water to sporulate. Morphological analysis indicated that the isolate is distinct from P. cranei and is described as a new species, P. ibarakiensis sp. nov. Pathogenicity tests of Chinese cabbage and cucumber seedlings indicated that the fungus grows as an endophyte and colonizes, inter and intracellularly, the root epidermal and cortical layers without causing apparent disease symptoms in the host. This endophyte showed the ability to support cucumber plant growth under conditions where NaNO3 was replaced by organic nitrogen but also conferred to Chinese cabbage the ability to grow at low pH. It also became successfully established in six other plants, including the Brassicae, Solanaceae, Poaceae, and Liliacea families, suggesting its adaptability to a broad range of host plants. PMID:24005845

  1. All that glitters is not Ramularia.

    PubMed

    Videira, S I R; Groenewald, J Z; Braun, U; Shin, H D; Crous, P W

    2016-01-01

    Ramularia is a species-rich genus that harbours plant pathogens responsible for yield losses to many important crops, including barley, sugar beet and strawberry. Species of Ramularia are hyphomycetes with hyaline conidiophores and conidia with distinct, thickened, darkened, refractive conidiogenous loci and conidial hila, and Mycosphaerella sexual morphs. Because of its simple morphology and general lack of DNA data in public databases, several allied genera are frequently confused with Ramularia. In order to improve the delimitation of Ramularia from allied genera and the circumscription of species within the genus Ramularia, a polyphasic approach based on multilocus DNA sequences, morphological and cultural data were used in this study. A total of 420 isolates belonging to Ramularia and allied genera were targeted for the amplification and sequencing of six partial genes. Although Ramularia and Ramulariopsis proved to be monophyletic, Cercosporella and Pseudocercosporella were polyphyletic. Phacellium isolates clustered within the Ramularia clade and the genus is thus tentatively reduced to synonymy under Ramularia. Cercosporella and Pseudocercosporella isolates that were not congeneric with the ex-type strains of the type species of those genera were assigned to existing genera or to the newly introduced genera Teratoramularia and Xenoramularia, respectively. Teratoramularia is a genus with ramularia-like morphology belonging to the Teratosphaeriaceae, and Xenoramularia was introduced to accommodate hyphomycetous species closely related to Zymoseptoria. The genera Apseudocercosporella, Epicoleosporium, Filiella, Fusidiella, Neopseudocercosporella, and Mycosphaerelloides were also newly introduced to accommodate species non-congeneric with their purported types. A total of nine new combinations and 24 new species were introduced in this study. PMID:27570325

  2. Graphene oxide exhibits broad-spectrum antimicrobial activity against bacterial phytopathogens and fungal conidia by intertwining and membrane perturbation

    NASA Astrophysics Data System (ADS)

    Chen, Juanni; Peng, Hui; Wang, Xiuping; Shao, Feng; Yuan, Zhaodong; Han, Heyou

    2014-01-01

    To understand the interaction mechanism between graphene oxide (GO) and typical phytopathogens, a particular investigation was conducted about the antimicrobial activity of GO against two bacterial pathogens (P. syringae and X. campestris pv. undulosa) and two fungal pathogens (F. graminearum and F. oxysporum). The results showed that GO had a powerful effect on the reproduction of all four pathogens (killed nearly 90% of the bacteria and repressed 80% macroconidia germination along with partial cell swelling and lysis at 500 μg mL-1). A mutual mechanism is proposed in this work that GO intertwinds the bacteria and fungal spores with a wide range of aggregated graphene oxide sheets, resulting in the local perturbation of their cell membrane and inducing the decrease of the bacterial membrane potential and the leakage of electrolytes of fungal spores. It is likely that GO interacts with the pathogens by mechanically wrapping and locally damaging the cell membrane and finally causing cell lysis, which may be one of the major toxicity actions of GO against phytopathogens. The antibacterial mode proposed in this study suggests that the GO may possess antibacterial activity against more multi-resistant bacterial and fungal phytopathogens, and provides useful information about the application of GO in resisting crop diseases.To understand the interaction mechanism between graphene oxide (GO) and typical phytopathogens, a particular investigation was conducted about the antimicrobial activity of GO against two bacterial pathogens (P. syringae and X. campestris pv. undulosa) and two fungal pathogens (F. graminearum and F. oxysporum). The results showed that GO had a powerful effect on the reproduction of all four pathogens (killed nearly 90% of the bacteria and repressed 80% macroconidia germination along with partial cell swelling and lysis at 500 μg mL-1). A mutual mechanism is proposed in this work that GO intertwinds the bacteria and fungal spores with a wide range of aggregated graphene oxide sheets, resulting in the local perturbation of their cell membrane and inducing the decrease of the bacterial membrane potential and the leakage of electrolytes of fungal spores. It is likely that GO interacts with the pathogens by mechanically wrapping and locally damaging the cell membrane and finally causing cell lysis, which may be one of the major toxicity actions of GO against phytopathogens. The antibacterial mode proposed in this study suggests that the GO may possess antibacterial activity against more multi-resistant bacterial and fungal phytopathogens, and provides useful information about the application of GO in resisting crop diseases. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr04941h

  3. Use of a Granular Bioplastic Formulation for Carrying Conidia of a Non-aflatoxigenic Strain of Aspergillus flavus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous research demonstrated that aflatoxin contamination in corn grown in Mississippi is reduced by field application of wheat grains pre-inoculated with the non-aflatoxigenic Aspergillus flavus strain NRRL 30797. To facilitate field applications of the biocontrol isolate, a series of laboratory ...

  4. HYPOCREA RUFA/TRICHODERMA VIRIDE: A REASSESSMENT, AND DESCRIPTION OF THREE CLOSELY RELATED SPECIES WITH AND WITHOUT WARTED CONIDIA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The type species of the genus Hypocrea (Hypocreaceae, Hypocreales, Ascomycota, Fungi), H. rufa, is re-defined and epitypified using a combination of phenotype (morphology of teleomorphs and anamorphs, and characteristics in culture) and phylogenetic analyses of the translation-elongation factor 1' g...

  5. Species-specific profiles of mycotoxins produced in cultures and associated with conidia of airborne fungi derived from biowaste.

    PubMed

    Fischer, G; Müller, T; Schwalbe, R; Ostrowski, R; Dott, W

    2000-10-01

    The potential to produce mycotoxins and non-volatile secondary metabolites was investigated for approximately 250 freshly isolated fungal strains. Among the eleven most relevant species, viz. Aspergillus flavus, A. fumigatus, A. niger, A. parasiticus, A. versicolor, Emericella nidulans, Paecilomyces variotii, Penicillium brevicompactum, P. clavigerum, P. crustosum, and P. polonicum, a wide range of metabolites partly of toxicological relevance was identified. Several unknown metabolites were found for the less frequent species, which were primarily investigated for chemotaxonomic delimitation from closely related species. The spectra of metabolites in conidial extracts and culture extracts (containing also mycelium and medium) were compared for a limited number of relevant fungi. Some mycotoxins, such as sterigmatocystin in Emericella nidulans, were not present in the conidial extracts, though produced by most strains. Fumigaclavine C, tryptoquivaline, and trypacidin, characteristic for A. fumigatus, were found in conidial extracts, but highly toxic compounds such as gliotoxin and fumitremorgens were not present. Finally, compounds such as cyclopenol, cyclopenin, and penitrem A being characteristic for certain penicillia, were found in conidial extracts and are therefore assumed to occur in native bioaerosols. PMID:11109562

  6. QUANTITATIVE MEASUREMENT OF STACHYBOTRYS CHARTARUM CONIDIA USING REAL TIME DETECTION OF PCR PRODUCTS WITH THE TAQMAN TM FLUOROGENIC PROBE SYSTEM

    EPA Science Inventory

    The occurence of Stachybotrys chartarum in indoor environments has been associated with a number of human health concerns, including fatal pulmonary haemosiderosis in infants. Currently used culture-based and microscopic methods of fungal species identification are poorly suited ...

  7. Using Soyscreen in an Oil-Based Biopesticide Formulation to Protect Beauveria bassiana Conidia from Degradation by Ultraviolet Light Energy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improving the efficacy of biological control treatments for pest control in crops will help to reduce dependence on chemical pesticide applications. Although effective for controlling insects, entomopathogenic microbes degrade rapidly when applied to field crops because of the adverse effects of su...

  8. Cover crop and conidia delivery system impacts on soil persistence of Metarhizium anisopliae (Hypocreales:Clavicipitaceae) in sugarbeet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sugarbeet root maggot, Tetanops myopaeformis (Röder), is a major North American pest of sugarbeet, Beta vulgaris L. Previous research suggests moderate field efficacy of the fungal entomopathogen Metarhizium anisopliae (Metch.) Sorok. against T. myopaeformis larvae. We conducted three-years of f...

  9. Potential of topic applications, leaf residues and soil drenches of the fungus Paecilomyces fumosoroseus (Deuteromycotina: Hyphomycetes) for management of the Diaprepes root weevil: laboratory and greenhouse investigations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diaprepes root weevil, (DRW) Diaprepes abbreviatus is a key pest of citrus and ornamental plants in Florida and Texas. DRW larvae burrow through the soil feeding on roots which when girdled causes secondary infection of the structural roots or root crown by Phytopthora spp. wherein mature citrus tre...

  10. Potential of two entomopathogenic fungi, Beauveria bassiana and Metarhizium anisopliae (Coleoptera: Scarabaeidae), as biological control agents against the June beetle.

    PubMed

    Erler, Fedai; Ates, A Ozgur

    2015-01-01

    The aim of this study was to evaluate the effectiveness of the entomopathogenic fungi (EPF), Beauveria bassiana (Bals.) Vuill. (Deuteromycotina: Hyphomycetes) strain PPRI 5339 [BroadBand, an emulsifiable spore concentrate (EC) formulation] and Metarhizium anisopliae (Metsch.) Sorokin (Hypocreales: Clavicipitaceae) strain F52 [Met52, both EC and granular (GR) formulations] against the larvae of Polyphylla fullo (L.) (Coleoptera: Scarabaeidae). Larvicidal bioassays were performed in foam boxes (100 by 75 by 50 cm; length by width by height), containing moist soil medium with some humus and potato tubers as food. Although the B. bassiana product (min. 4 × 10(9) conidia/ml) was applied at 100, 150, and 200 ml/100 l water; M. anisopliae strain F52 was applied at 500, 1,000, and 1,500 g/m(3) of moist soil medium for GR (9 × 10(8) cfu/g) and 75, 100, and 125 ml/100 l water for EC (5.5 × 10(9) conidia/ml) formulation. Both fungi were pathogenic to larvae of the pest; however, young larvae (1st and 2nd instars) were more susceptible to infection than older ones (3rd instar). Mortality rates of young and older larvae varied with conidial concentration of both fungi and elapsed time after application. The B. bassiana product was more effective than both of the formulations of the M. anisopliae product, causing mortalities up to 79.8 and 71.6% in young and older larvae, respectively. The highest mortality rates of young and older larvae caused by the M. anisopliae product were 74.1 and 67.6% for the GR formulation, 70.2 and 61.8% for the EC formulation, respectively. These results may suggest that both fungi have potential to be used for management of P. fullo. PMID:25881632

  11. Potential of two entomopathogenic fungi, Beauveria bassiana and Metarhizium anisopliae (Coleoptera: Scarabaeidae), as biological control agents against the June beetle

    PubMed Central

    Erler, Fedai; Ates, A. Ozgur

    2015-01-01

    The aim of this study was to evaluate the effectiveness of the entomopathogenic fungi (EPF), Beauveria bassiana (Bals.) Vuill. (Deuteromycotina: Hyphomycetes) strain PPRI 5339 [BroadBand, an emulsifiable spore concentrate (EC) formulation] and Metarhizium anisopliae (Metsch.) Sorokin (Hypocreales: Clavicipitaceae) strain F52 [Met52, both EC and granular (GR) formulations] against the larvae of Polyphylla fullo (L.) (Coleoptera: Scarabaeidae). Larvicidal bioassays were performed in foam boxes (100 by 75 by 50 cm; length by width by height), containing moist soil medium with some humus and potato tubers as food. Although the B. bassiana product (min. 4 × 109 conidia/ml) was applied at 100, 150, and 200 ml/100 l water; M. anisopliae strain F52 was applied at 500, 1,000, and 1,500 g/m3 of moist soil medium for GR (9 × 108 cfu/g) and 75, 100, and 125 ml/100 l water for EC (5.5 × 109 conidia/ml) formulation. Both fungi were pathogenic to larvae of the pest; however, young larvae (1st and 2nd instars) were more susceptible to infection than older ones (3rd instar). Mortality rates of young and older larvae varied with conidial concentration of both fungi and elapsed time after application. The B. bassiana product was more effective than both of the formulations of the M. anisopliae product, causing mortalities up to 79.8 and 71.6% in young and older larvae, respectively. The highest mortality rates of young and older larvae caused by the M. anisopliae product were 74.1 and 67.6% for the GR formulation, 70.2 and 61.8% for the EC formulation, respectively. These results may suggest that both fungi have potential to be used for management of P. fullo. PMID:25881632

  12. Species and ecological diversity within the Cladosporium cladosporioides complex (Davidiellaceae, Capnodiales).

    PubMed

    Bensch, K; Groenewald, J Z; Dijksterhuis, J; Starink-Willemse, M; Andersen, B; Summerell, B A; Shin, H-D; Dugan, F M; Schroers, H-J; Braun, U; Crous, P W

    2010-01-01

    The genus Cladosporium is one of the largest genera of dematiaceous hyphomycetes, and is characterised by a coronate scar structure, conidia in acropetal chains and Davidiella teleomorphs. Based on morphology and DNA phylogeny, the species complexes of C. herbarum and C. sphaerospermum have been resolved, resulting in the elucidation of numerous new taxa. In the present study, more than 200 isolates belonging to the C. cladosporioides complex were examined and phylogenetically analysed on the basis of DNA sequences of the nuclear ribosomal RNA gene operon, including the internal transcribed spacer regions ITS1 and ITS2, the 5.8S nrDNA, as well as partial actin and translation elongation factor 1-α gene sequences. For the saprobic, widely distributed species Cladosporium cladosporioides, both a neotype and epitype are designated in order to specify a well established circumscription and concept of this species. Cladosporium tenuissimum and C. oxysporum, two saprobes abundant in the tropics, are epitypified and shown to be allied to, but distinct from C. cladosporioides. Twenty-two species are newly described on the basis of phylogenetic characters and cryptic morphological differences. The most important phenotypic characters for distinguishing species within the C. cladosporioides complex, which represents a monophyletic subclade within the genus, are shape, width, length, septation and surface ornamentation of conidia and conidiophores; length and branching patterns of conidial chains and hyphal shape, width and arrangement. Many of the treated species, e.g., C. acalyphae, C. angustisporum, C. australiense, C. basiinflatum, C. chalastosporoides, C. colocasiae, C. cucumerinum, C. exasperatum, C. exile, C. flabelliforme, C. gamsianum, and C. globisporum are currently known only from specific hosts, or have a restricted geographical distribution. A key to all species recognised within the C. cladosporioides complex is provided. PMID:20877444

  13. Species and ecological diversity within the Cladosporium cladosporioides complex (Davidiellaceae, Capnodiales)

    PubMed Central

    Bensch, K.; Groenewald, J.Z.; Dijksterhuis, J.; Starink-Willemse, M.; Andersen, B.; Summerell, B.A.; Shin, H.-D.; Dugan, F.M.; Schroers, H.-J.; Braun, U.; Crous, P.W.

    2010-01-01

    The genus Cladosporium is one of the largest genera of dematiaceous hyphomycetes, and is characterised by a coronate scar structure, conidia in acropetal chains and Davidiella teleomorphs. Based on morphology and DNA phylogeny, the species complexes of C. herbarum and C. sphaerospermum have been resolved, resulting in the elucidation of numerous new taxa. In the present study, more than 200 isolates belonging to the C. cladosporioides complex were examined and phylogenetically analysed on the basis of DNA sequences of the nuclear ribosomal RNA gene operon, including the internal transcribed spacer regions ITS1 and ITS2, the 5.8S nrDNA, as well as partial actin and translation elongation factor 1-α gene sequences. For the saprobic, widely distributed species Cladosporium cladosporioides, both a neotype and epitype are designated in order to specify a well established circumscription and concept of this species. Cladosporium tenuissimum and C. oxysporum, two saprobes abundant in the tropics, are epitypified and shown to be allied to, but distinct from C. cladosporioides. Twenty-two species are newly described on the basis of phylogenetic characters and cryptic morphological differences. The most important phenotypic characters for distinguishing species within the C. cladosporioides complex, which represents a monophyletic subclade within the genus, are shape, width, length, septation and surface ornamentation of conidia and conidiophores; length and branching patterns of conidial chains and hyphal shape, width and arrangement. Many of the treated species, e.g., C. acalyphae, C. angustisporum, C. australiense, C. basiinflatum, C. chalastosporoides, C. colocasiae, C. cucumerinum, C. exasperatum, C. exile, C. flabelliforme, C. gamsianum, and C. globisporum are currently known only from specific hosts, or have a restricted geographical distribution. A key to all species recognised within the C. cladosporioides complex is provided. PMID:20877444

  14. Morphology, phylogeny and biology of Gliocephalis hyalina, a biotrophic contact mycoparasite of Fusarium species.

    PubMed

    Jacobs, K; Holtzman, Kim; Seifert, Keith A

    2005-01-01

    Gliocephalis hyalina, a rarely seen microfungus with a morphology similar to the hyphomycete genus Aspergillus but with slimy conidia was found in a mixed microbial culture from soybean roots. This species has been reported sporadically since 1899, each time in association with other fungi or bacteria. Gliocephalis hyalina has not been maintained in monoxenic culture and requires other fungi to grow. Light and scanning electron microcope studies indicate that it is a biotrophic contact parasite of Fusarium species. The fungus may penetrate the cells but has no apparent deleterious effect on the growth or plant pathogenicity of its host. Phylogenetic analyses of partial nuclear small subunit rDNA sequences place G. hyalina near the Laboulbeniales, an order of obligate insect parasitic microfungi, and the related mycelial genus Pyxidiophora. Gliocephalis hyalina is mycoparasitic along with many Pyxidiophora species. These discoveries suggest that some "unculturable" microorganisms or "cryptic DNA" recovered from environmental DNA samples might represent obligate biotrophs that could be cultured and studied with simple techniques. PMID:16389962

  15. Common but different: The expanding realm of Cladosporium

    PubMed Central

    Bensch, K.; Groenewald, J.Z.; Braun, U.; Dijksterhuis, J.; de Jesús Yáñez-Morales, M.; Crous, P.W.

    2015-01-01

    The genus Cladosporium (Cladosporiaceae, Dothideomycetes), which represents one of the largest genera of dematiaceous hyphomycetes, has been intensively investigated during the past decade. In the process, three major species complexes (C. cladosporioides, C. herbarum and C. sphaerospermum) were resolved based on morphology and DNA phylogeny, and a monographic revision of the genus (s. lat.) published reflecting the current taxonomic status quo. In the present study a further 19 new species are described based on phylogenetic characters (nuclear ribosomal RNA gene operon, including the internal transcribed spacer regions ITS1 and ITS2, as well as partial actin and translation elongation factor 1-α gene sequences) and morphological differences. For a selection of the species with ornamented conidia, scanning electron microscopic photos were prepared to illustrate the different types of surface ornamentation. Surprisingly, during this study Cladosporium ramotenellum was found to be a quite common saprobic species, being widely distributed and occurring on various substrates. Therefore, an emended species description is provided. Furthermore, the host range and distribution data for several previously described species are also expanded. PMID:26955200

  16. [Cultural Properties and Taxonomic Position of Helminthosporium-Like Fungal Isolates from the White Sea].

    PubMed

    Kireev, Ya V; Konovalova, O P; Myuge, N S; Shnyreva, A V; Bubnova, E N

    2015-01-01

    Morphological, cultural and physiological characteristics of 19 Helminthosporium-like hyphomycetes isolated from the White Sea were studied. Taxonomic status of the isolates was verified using molecular genetics techniques. One of the isolates was identified as Alternatia sp., while the rest of marine isolates belonged to the species Paradendriphiella salina (G.K. Sutherl.) Woudenb. & Crous. The specific features of the isolates studied were characterized as adaptive. Optimum salinity for their growth was 1-2% NaCl, which is lower than the value for the known open ocean isolates. This is probably due to relatively low salinity of White Sea (22-24 per thousand) as compared with the ocean water (35 per thousand). While the temperature optimum for growth was 22 per thousand, growth and sporulation occurred at 6 degrees C, which has not been reported for marine fungi isolated from warmer seawater. All isolates studied grew and sporulated efficiently on the medium supplied with the Fucus algae extract and in the sea water layer. Conidia of the isolates submerged in the sea water were propagated efficiently, unlike the soil-born fungi. Holoblastic conidiogenesis was demonstrated by light and scanning electron microscopy, confirming the separation of P. salina from the genus Scolecobasidium. PMID:27169247

  17. [Isolation, identification and anticancer activity of an endophytic fungi from Juglans mandshurica].

    PubMed

    Li, Meiya; Wu, Yunwei; Jiang, Fusheng; Yu, Xiangli; Tang, Kexuan; Miao, Zhiqi

    2009-07-01

    The endophytic fungus named FSN006 was isolated from the inner bark of Juglans mandshurica. It grew quickly and formed circular colony on PDA plate. The upper side of the colony was white, while the lower side of the colony and the conditioned medium were light yellow as a result of significant yellow pigment substances were produced and secreted by the fungi. Green elliptic conidia appeared when cultured on CMX plate. Based on the morphology identification and ITS sequence, it was clear that this fungus belonged to the Deuteromycotina, HyPhomycetes, Moniliales, Trichoderma longibrachiatum. The conditioned medium of FSN006 showed a high anti-tumor ability against liver cancer cell-HepG2, and reached its IC50 concentration after being diluted 20 times, while the IC50 concentration of curcumine was(11.49 +/- 0.12) mg x L(-1). In addition, there was preeminent selective inhibiting effect against the normal liver cell strain HL-7702 and its caner counter strain HepG2. The inhibiting effect against strain HL-7702 was only one quarter of that against HepG2 at the concentration of IC50. Therefore, the fermentation of FSN006 may provide a possible way to produce anticancer drug with higher efficiency and lower toxicity. PMID:19873766

  18. A RAPID METHOD FOR THE EXTRACTION OF FUNGAL DNA FROM ENVIRONMENTAL SAMPLES: EVALUATION IN THE QUANTITATIVE ANALYSIS OF MEMNONIELLA ECHINATA CONIDIA USING REAL TIME DETECTION OF PCR PRODUCTS

    EPA Science Inventory

    New technologies are creating the potential for using nucleic acid sequence detection to perform routine microbiological analyses of environmental samples. Our laboratory has recently reported on the development of a method for the quantitative detection of Stachybotrys chartarum...

  19. Loss of msnA, a putative stress regulatory gene, in Aspergillus parasiticus and Aspergillus flavus increased production of conidia, aflatoxins and kojic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Production of the harmful carcinogenic aflatoxins by Aspergillus parasiticus and Aspergillus flavus has been postulated to be a mechanism to relieve oxidative stress. The msnA gene, the ortholog of Saccharomyces cerevisiae MSN2 associated with multi-stress response, of the two species was disrupted....

  20. Pathogenicity of conidia-based preparations of entomopathogenic fungi against the greenhouse pest aphids: green peach aphid, melon aphid, and foxglove aphid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seeking new isolates of entomopathogenic fungi with greater virulence against greenhouse aphid pests than those currently registered in North America for control of these insects, single-dose screening assays of 44 selected fungal isolates and 4 commercially available strains were conducted against ...

  1. Application of modified atmosphere packaging (gas flushing and active packaging) for extending the shelf life of Beauveria bassiana conidia at high temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Limited shelf life has long been a major constraint to the development of fungus-based bioinsecticides (mycoinsecticides). Fungal spores comprising the active ingredients of most products typically lose viability within a few months when stored in conventional packaging at temperatures >30 deg C. Me...

  2. Selection of Wetting Agent for Dried Conidia of two Beauveria bassiana Strains from Different Production Systems to Control Tarnished Plant Bugs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The hydrophilic–lipophilic balance (HLB) number was used to select surfactant, TDA (polyoxy-ethylene tridecyl ether) with a range of HLB numbers in formulation development of two Beauveria bassiana strains, NI8 and GHA produced from different systems. The results indicated that optimal HLB number of...

  3. Loss of msnA, a Putative Stress Regulatory Gene, in Aspergillus parasiticus and Aspergillus flavus Increased Production of Conidia, Aflatoxins and Kojic Acid

    PubMed Central

    Chang, Perng-Kuang; Scharfenstein, Leslie L.; Luo, Meng; Mahoney, Noreen; Molyneux, Russell J.; Yu, Jiujiang; Brown, Robert L.; Campbell, Bruce C.

    2011-01-01

    Production of the harmful carcinogenic aflatoxins by Aspergillus parasiticus and Aspergillus flavus has been postulated to be a mechanism to relieve oxidative stress. The msnA gene of A. parasiticus and A. flavus is the ortholog of Saccharomyces cerevisiae MSN2 that is associated with multi-stress response. Compared to wild type strains, the msnA deletion (∆msnA) strains of A. parasiticus and A. flavus exhibited retarded colony growth with increased conidiation. The ∆msnA strains also produced slightly higher amounts of aflatoxins and elevated amounts of kojic acid on mixed cereal medium. Microarray assays showed that expression of genes encoding oxidative stress defense enzymes, i.e., superoxide dismutase, catalase, and cytochrome c peroxidase in A. parasiticus ∆msnA, and the catalase A gene in A. flavus ∆msnA, was up-regulated. Both A. parasiticus and A. flavus ∆msnA strains produced higher levels of reactive oxygen species (ROS), and ROS production of A. flavus msnA addback strains was decreased to levels comparable to that of the wild type A. flavus. The msnA gene appears to be required for the maintenance of the normal oxidative state. The impairment of msnA resulted in the aforementioned changes, which might be used to combat the increased oxidative stress in the cells. PMID:22069691

  4. Susceptibility screening of hyphae-forming fungi with a new, easy, and fast inoculum preparation method.

    PubMed

    Schmalreck, Arno; Willinger, Birgit; Czaika, Viktor; Fegeler, Wolfgang; Becker, Karsten; Blum, Gerhard; Lass-Flörl, Cornelia

    2012-12-01

    In vitro susceptibility testing of clinically important fungi becomes more and more essential due to the rising number of fungal infections in patients with impaired immune system. Existing standardized microbroth dilution methods for in vitro testing of molds (CLSI, EUCAST) are not intended for routine testing. These methods are very time-consuming and dependent on sporulating of hyphomycetes. In this multicentre study, a new (independent of sporulation) inoculum preparation method (containing a mixture of vegetative cells, hyphae, and conidia) was evaluated. Minimal inhibitory concentrations (MIC) of amphotericin B, posaconazole, and voriconazole of 180 molds were determined with two different culture media (YST and RPMI 1640) according to the DIN (Deutsches Institut für Normung) microdilution assay. 24 and 48 h MIC of quality control strains, tested per each test run, prepared with the new inoculum method were in the range of DIN. YST and RPMI 1640 media showed similar MIC distributions for all molds tested. MIC readings at 48 versus 24 h yield 1 log(2) higher MIC values and more than 90 % of the MICs read at 24 and 48 h were within ± 2 log(2) dilution. MIC end point reading (log(2 MIC-RPMI 1640)-log(2 MIC-YST)) of both media demonstrated a tendency to slightly lower MICs with RPMI 1640 medium. This study reports the results of a new, time-saving, and easy-to-perform method for inoculum preparation for routine susceptibility testing that can be applied for all types of spore-/non-spore and hyphae-forming fungi. PMID:22864604

  5. Evaluation of Metarhizium anisopliae, Beauveria bassiana and Paecilomyces fumosoroseus as entomopathogens of the cactus moth, Cactoblastis cactorum (Lepidoptera:Pyralidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungal pathogens Metarhizium anisopliae (Metchnikoff) Sorokin (Hypocreales: Clavicipitaceae), Paecilomyces fumosoroseus (Wize) Brown & Smith (Deuteromycotina: Hyphomycetes), and Beauveria bassiana (Bals.-Criv.) Vuill. (Hypocreales: Clavicipitaceae) were evaluated as potential biological control ...

  6. Diaphorina citri (Hemiptera: Psyllidae) infection and dissemination of the entomopathogenic fungus Isaria fumosorosea (Hypocreales: Cordycipitaceae)under laboratory conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A method was developed to increase efficacy and reduce grower costs when using the biological control fungal agent Paecilomyces fumosoroseus blastospores (Deuteromycotina: Hyphomycetes) to infect adult Asian citrus psyllids, Diaphorina citri (Psyllidae: Hemiptera). We analyzed the efficacy of this ‘...

  7. Polykaryon formation using a swollen conidium of Trichoderma reesei.

    PubMed

    Toyama, Hideo; Yano, Makiko; Hotta, Takeshi

    2004-01-01

    The cellulolytic fungus, Trichoderma has oval and mononucleate conidia. When these conidia are incubated in a liquid medium, they begin to swell and their shape becomes spherical followed by an increase in inner space. In such swollen conidia, it is possible to produce a larger autopolyploid nucleus using a mitotic arrester compared with the case of the original conidia. In this study, polykaryon formation was attempted using these swollen conidia. Dried mature green conidia of Trichoderma reesei QM6a (IFO 31326) were incubated in Mandel's medium in order to swell. The swollen conidia were treated with a mitotic arrester, colchicine, for autopolyploidization. After autopolyploidization, polykaryon formation was carried out using the swollen conidia. After the treatment, multiple smaller nuclei whose diameter was almost the same as that of the original strain were generated from an autopolyploid nucleus in a swollen conidium. A cellulase hyperproducer without decrease in growth rate could be selected using such swollen conidia. PMID:15054260

  8. GENE EXPRESSION ANALYSIS OF CONIDIUM MATURATION AND GERMINATION IN FUSARIUM GRAMINEARUM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To understand the infection cycle of the head blight pathogen F. graminearum, gene expression profiles were monitored in newly formed conidia, conidia that had been desiccated for 10 days and germinating conidia using the 18K feature F. graminearum Affymetrix GeneChip. A total of 6,384 positive sign...

  9. Metulocladosporiella gen. nov. for the causal organism of Cladosporium speckle disease of banana.

    PubMed

    Crous, Pedro W; Schroers, Hans-Josef; Groenewald, Johannes Z; Braun, Uwe; Schubert, Konstanze

    2006-03-01

    Cladosporium musae, a widespread leaf-spotting hyphomycete on Musa spp., is genetically and morphologically distinct from Cladosporium s. str. (Davidiella anamorphs, Mycosphaerellaceae, Dothideales). DNA sequence data derived from the ITS and LSU gene regions of C. musae isolates show that this species is part of a large group of hyphomycetes in the Chaetothyriales with dematiaceous blastoconidia in acropetal chains. Cladosporium adianticola, a foliicolous hyphomycete known from leaf litter in Cuba is also a member of this clade and is closely related to C. musae. A comparison with other genera in the Cladosporium complex revealed that C. musae belongs to a lineage for which no generic name is currently available, and for which the genus Metulocladosporiella gen. nov. is proposed. Two species of Metulocladosporiella are currently known, namely M. musae, which is widely distributed, and M. musicola sp. nov., which is currently known from Africa. PMID:16483752

  10. Do Invertebrate Activity and Current Velocity Affect Fungal Assemblage Structure in Leaves?

    NASA Astrophysics Data System (ADS)

    Ferreira, Verónica; Graça, Manuel A. S.

    2006-02-01

    In this study we assessed the effect of current velocity and shredder presence, manipulated in artificial channels, on the structure of the fungal assemblage colonizing alder (Alnus glutinosa (L.) Gaertner) leaves incubated in coarse and fine mesh bags. Fungal sporulation rates, cumulative conidial production and number of species of aquatic hyphomycetes were higher in leaves exposed to high rather than to low current velocity. The opposite was observed regarding Simpson's index (D) on the fungal assemblage. Some species of aquatic hyphomycetes were consistently stimulated in high current channels. No effect of shredders or of mesh type was observed.

  11. Potassium influences forage bermudagrass yield and fungal leaf disease severity in Mississippi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leaf spot diseases are associated with K deficiency in forage bermudagrass. In 2010, a natural disease epiphytotic caused by six species of Bipolaris, Curvularia, and Exserohilum (dematiaceous hyphomycetes) was evaluated in 56 plots of ‘Tifton 44' bermudagrass in Mississippi. Pathogen occurrence, di...

  12. Subcutaneous phaeohyphomycosis due to Phialemoniopsis ocularis successfully treated by voriconazole

    PubMed Central

    Desoubeaux, Guillaume; García, Dania; Bailly, Eric; Augereau, Olivier; Bacle, Guillaume; De Muret, Anne; Bernard, Louis; Cano-Lira, José F.; Garcia-Hermoso, Dea; Chandenier, Jacques

    2014-01-01

    We report a case of subcutaneous infection in a 67 year-old Cambodian man who presented with a 5-month history of swelling of the right foot. Histopathology was compatible with phaeohyphomycosis and the hyphomycete Phialemoniopsis ocularis was identified by the means of morphological and molecular techniques. The patient responded well to a 6-month oral treatment with voriconazole alone. PMID:24936402

  13. Ulocladium atrum Keratitis

    PubMed Central

    Badenoch, P. R.; Halliday, C. L.; Ellis, D. H.; Billing, K. J.; Mills, R. A. D.

    2006-01-01

    We report a case of Ulocladium atrum keratitis in a 43-year-old man. No predisposing event was known. He received natamycin and fluconazole drops and the infection resolved. The isolate was identified by morphological and rRNA gene sequence analyses. U. atrum is a dematiaceous hyphomycete not hitherto reported to infect humans. PMID:16517929

  14. Microsatellite variability in the entomopathogenic fungus Paeciolomyces fumosoroseus: genetic diversity and population structure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The hyphomycete Paecilomyces fumosoroseus (Pfr) is a geographically widespread fungus capable of infecting various insect hosts. The fungus has been used for the biological control of several important insect pests of agriculture. However knowledge of the fungus’ genetic diversity and population str...

  15. Stachbotrys Root Rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stachybotrys root rot is caused by Stachybotrys chartarum, a cellulytic saprophytic hyphomycete fungus. The pathogen produces mycotoxins including a host of immunosupressant compounds for human and is one of the causes of the "sick building syndrome." Although S. chartarum is rarely known as a plan...

  16. Two new species of Stemphylium from Northwest China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During surveys of hyphomycetes from the Northwest of China, two undescribed taxa of Stemphylium were discovered from diseased leaves of Malus sieversii and Pyrus sinkiangensis in Sinkiang Provence, which are described as S. mali and S. pyrinum. The two species differ from similar species morphologi...

  17. Effect of heat stress and oil formulation on conidial germination of Metarhizium anisopliae s.s. on tick cuticle and artificial medium.

    PubMed

    Barreto, Lucas P; Luz, Christian; Mascarin, Gabriel M; Roberts, Donald W; Arruda, Walquíria; Fernandes, Éverton K K

    2016-07-01

    The effect of heat stress (45°C) versus non-heat stress (27°C) on germination of Metarhizium anisopliae sensu stricto (s.s.) isolate IP 119 was examined with conidia formulated (suspended) in pure mineral oil or in water (Tween 80, 0.01%), and then applied onto the cuticle of Rhipicephalus sanguineus sensu lato (s.l.) engorged females or onto culture medium (PDAY). In addition, bioassays were performed to investigate the effect of conidia heated while formulated in oil, then applied to blood-engorged adult R. sanguineus females. Conidia suspended in water then exposed to 45°C, in comparison to conidia formulated in mineral oil and exposed to the same temperature, germinated less and more slowly when incubated on either PDAY medium or tick cuticle. Also, conidial germination on tick cuticle was delayed in comparison to germination on artificial culture medium; for example, germination was 13% on tick cuticle 72h after inoculation, in contrast to 61.5% on PDAY medium. Unheated (27°C) conidia suspended in either water or oil and applied to tick cuticle developed appressoria 36h after treatment; whereas only heat-stressed conidia formulated in oil developed appressoria on tick cuticle. In comparison to conidia heated in mineral oil, there was a strong negative effect of heat on germination of conidia heated in water before being applied to arthropod cuticle. Nevertheless, bioassays [based primarily on egg production (quantity) and egg hatchability] exhibited high percentages of tick control regardless of the type of conidial suspension; i.e., water- or oil-formulated conidia, and whether or not conidia were previously exposed to heat. In comparison to aqueous conidial preparations, however, conidia formulated in oil reduced egg hatchability irrespective of heat or no-heat exposure. In conclusion, mineral-oil formulation protected conidia against heat-induced delay of both germination and appressorium production when applied to the cuticle of R. sanguineus. PMID

  18. Efficacy of Bauveria bassiana for red flour beetle when applied with plant essential oils or in mineral oil and organosilicone carriers.

    PubMed

    Akbar, Waseem; Lord, Jeffrey C; Nechols, James R; Loughin, Thomas M

    2005-06-01

    The carriers mineral oil and Silwet L-77 and the botanical insecticides Neemix 4.5 and Hexacide were evaluated for their impacts on the efficacy of Beauveria bassiana (Balsamo) Vuillemin conidia against red flour beetle, Tribolium castaneum (Herbst), larvae. The dosages of liquid treatments were quantified by both conidia concentration in the spray volume and conidia deposition on the target surface. The latter approach allowed comparison with dry, unformulated conidia. The median lethal concentrations of B. bassiana in 0.05% Silwet L-77 solution or without a carrier were approximately double that for conidia in mineral oil. Carriers had highly significant effects on the efficacy of B. bassiana. The lower efficacy of conidia in aqueous Silwet L-77 may have been the result of conidia loss from the larval surface because of the siloxane's spreading properties. Neemix 4.5 (4.5% azadirachtin) delayed pupation and did not reduce the germination rate of B. bassiana conidia, but it significantly reduced T. castaneum mortality at two of four tested fungus doses. Hexacide (5% rosemary oil) caused significant mortality when applied without B. bassiana, but it did not affect pupation, the germination rate of conidia, or T. castaneum mortality when used in combination with the fungus. PMID:16022293

  19. Morphology and molecular taxonomy of Evlachovaea-like fungi, and the status of this unusual conidial genus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The entomopathogenic anamorphic genus Evlachovaea was described to differ from other fungi in forming its conidia obliquely to the axis of the conidiogenous cell and with successive conidia having alternate orientations with a zipper- or chevron-like arrangement resulting in flat, ribbon-like chains...

  20. Colonization by Cladosporium spp. of painted metal surfaces associated with heating and air conditioning systems

    NASA Technical Reports Server (NTRS)

    Ahearn, D. G.; Simmons, R. B.; Switzer, K. F.; Ajello, L.; Pierson, D. L.

    1991-01-01

    Cladosporium cladosporioides and C. hebarum colonized painted metal surfaces of covering panels and register vents of heating, air conditioning and ventilation systems. Hyphae penetrated the paint film and developed characteristic conidiophores and conidia. The colonies were tightly appressed to the metal surface and conidia were not readily detectable via standard air sampling procedures.

  1. Interaction of Aceria mangiferae with Fusarium mangiferae, the causal agent of mango malformation disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The study examines the role of the mango bud mite, Aceria mangiferae, in carrying Fusarium mangiferae’s conidia, vectoring them into the penetration sites and assisting fungal penetration and dissemination. Conidia that were exposed to a green fluorescent protein (gfp)-marked isolate of F. mangifer...

  2. Ulocladium cantlous sp. nov. isolated from Northwest China: morphology and molecular phylogenetic position

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new species of Ulocladium was isolated from diseased leaves from two Cucumis spp. growing in Sinkiang and Gansu Provinces of China. Conidia were isolated from diseased leaf areas, grown in single-spore pure culture, and conidia harvested 1, 3, and 7 days after incubation for morphological comparis...

  3. FleA Expression in Aspergillus fumigatus Is Recognized by Fucosylated Structures on Mucins and Macrophages to Prevent Lung Infection.

    PubMed

    Kerr, Sheena C; Fischer, Gregory J; Sinha, Meenal; McCabe, Orla; Palmer, Jonathan M; Choera, Tsokyi; Lim, Fang Yun; Wimmerova, Michaela; Carrington, Stephen D; Yuan, Shaopeng; Lowell, Clifford A; Oscarson, Stefan; Keller, Nancy P; Fahy, John V

    2016-04-01

    The immune mechanisms that recognize inhaled Aspergillus fumigatus conidia to promote their elimination from the lungs are incompletely understood. FleA is a lectin expressed by Aspergillus fumigatus that has twelve binding sites for fucosylated structures that are abundant in the glycan coats of multiple plant and animal proteins. The role of FleA is unknown: it could bind fucose in decomposed plant matter to allow Aspergillus fumigatus to thrive in soil, or it may be a virulence factor that binds fucose in lung glycoproteins to cause Aspergillus fumigatus pneumonia. Our studies show that FleA protein and Aspergillus fumigatus conidia bind avidly to purified lung mucin glycoproteins in a fucose-dependent manner. In addition, FleA binds strongly to macrophage cell surface proteins, and macrophages bind and phagocytose fleA-deficient (∆fleA) conidia much less efficiently than wild type (WT) conidia. Furthermore, a potent fucopyranoside glycomimetic inhibitor of FleA inhibits binding and phagocytosis of WT conidia by macrophages, confirming the specific role of fucose binding in macrophage recognition of WT conidia. Finally, mice infected with ΔfleA conidia had more severe pneumonia and invasive aspergillosis than mice infected with WT conidia. These findings demonstrate that FleA is not a virulence factor for Aspergillus fumigatus. Instead, host recognition of FleA is a critical step in mechanisms of mucin binding, mucociliary clearance, and macrophage killing that prevent Aspergillus fumigatus pneumonia. PMID:27058347

  4. Influence of temperature and humidity on survival of Penicillium digitatum and Geotrichum citri-aurantii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Longevity of conidia of Penicillium digitatum and arthrospores of Geotrichum citri-aurantii, cause of green mold and sour rot of citrus, respectively, was determined. Conidia of P. digitatum were exposed to ambient summer conditions in central California or to conditions of controlled temperature an...

  5. Biological control of Spreading Dayflower (Commelina diffusa) with the fungal pathogen Phoma commelinicola

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Greenhouse and field experiments showed that conidia of the fungal pathogen, Phoma commelinicola exhibited bioherbicidal activity on spreading dayflower (Commelina diffusa) seedlings when applied at concentrations of 106 to 109 conidia ml-1. Greenhouse tests determined an optimal temperature for co...

  6. Presence of adhesive vesicles in the mycoherbicide Alternaria helianthi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alternaria helianthi conidia have been shown to cause disease on common cocklebur. Conidia were applied to slides made hydrophobic by coating with dimethyldicholorosilane (mimics leaf surface), then rinsed and treated with FITC-Con A to stain the adhesive material. Alternaria helianthi coni...

  7. Comparative efficacy of emulsifiable-oil, wettable-powder, and unformulated-powder preparations of Beauveria bassiana against the melon aphid Aphis gossypii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aphicidal efficacy of two commercial formulations of Beauveria bassiana strain GHA conidia, an emulsifiable-paraffinic oil dispersion (OD) and a clay-based wettable powder (WP), were compared to unformulated conidia in laboratory tests with adult melon aphids (Aphis gossypii). For the initial 24 hou...

  8. FleA Expression in Aspergillus fumigatus Is Recognized by Fucosylated Structures on Mucins and Macrophages to Prevent Lung Infection

    PubMed Central

    Sinha, Meenal; McCabe, Orla; Palmer, Jonathan M.; Choera, Tsokyi; Yun Lim, Fang; Wimmerova, Michaela; Carrington, Stephen D.; Yuan, Shaopeng; Lowell, Clifford A.; Oscarson, Stefan; Keller, Nancy P.; Fahy, John V.

    2016-01-01

    The immune mechanisms that recognize inhaled Aspergillus fumigatus conidia to promote their elimination from the lungs are incompletely understood. FleA is a lectin expressed by Aspergillus fumigatus that has twelve binding sites for fucosylated structures that are abundant in the glycan coats of multiple plant and animal proteins. The role of FleA is unknown: it could bind fucose in decomposed plant matter to allow Aspergillus fumigatus to thrive in soil, or it may be a virulence factor that binds fucose in lung glycoproteins to cause Aspergillus fumigatus pneumonia. Our studies show that FleA protein and Aspergillus fumigatus conidia bind avidly to purified lung mucin glycoproteins in a fucose-dependent manner. In addition, FleA binds strongly to macrophage cell surface proteins, and macrophages bind and phagocytose fleA-deficient (∆fleA) conidia much less efficiently than wild type (WT) conidia. Furthermore, a potent fucopyranoside glycomimetic inhibitor of FleA inhibits binding and phagocytosis of WT conidia by macrophages, confirming the specific role of fucose binding in macrophage recognition of WT conidia. Finally, mice infected with ΔfleA conidia had more severe pneumonia and invasive aspergillosis than mice infected with WT conidia. These findings demonstrate that FleA is not a virulence factor for Aspergillus fumigatus. Instead, host recognition of FleA is a critical step in mechanisms of mucin binding, mucociliary clearance, and macrophage killing that prevent Aspergillus fumigatus pneumonia. PMID:27058347

  9. Use of a Monoclonal Antibody-Based Immunoassay for the Detection and Quantification of Heliscus lugdunensis Colonizing Alder Leaves and Roots.

    PubMed

    Bermingham, S.; Dewey, F.M.; Fisher, P.J.; Maltby, L.

    2001-12-01

    A genus-specific monoclonal antibody, NG-CF10, raised in a previous study to the fungal pathogen Nectria galligena, was found to recognize the aquatic hyphomycete Heliscus lugdunensis (anamorph) and its teleomorph Nectria lugdunensis. Using this MAb in a plate trapped antigen- ELISA we could detect and determine the biomass of Heliscus lugdunensis in mixed assemblages in both naturally occurring and artificially inoculated leaves and roots of Alnus glutinosa trees. Initial studies indicate that the biomass associated with naturally occurring leaf material is significantly lower than that recorded with laboratory inoculated leaves, suggesting that biomass production is limited in the natural environment. Significantly lower biomass was associated with roots when compared with leaf material, which supports the proposition that rather than a major substrate for the growth of aquatic hyphomycetes, roots act as a refugium for fungal growth. PMID:12024233

  10. Comparative transcriptomics of infectious spores from the fungal pathogen Histoplasma capsulatum reveals a core set of transcripts that specify infectious and pathogenic states.

    PubMed

    Inglis, Diane O; Voorhies, Mark; Hocking Murray, Davina R; Sil, Anita

    2013-06-01

    Histoplasma capsulatum is a fungal pathogen that infects both healthy and immunocompromised hosts. In regions where it is endemic, H. capsulatum grows in the soil and causes respiratory and systemic disease when inhaled by humans. An interesting aspect of H. capsulatum biology is that it adopts specialized developmental programs in response to its environment. In the soil, it grows as filamentous chains of cells (mycelia) that produce asexual spores (conidia). When the soil is disrupted, conidia aerosolize and are inhaled by mammalian hosts. Inside a host, conidia germinate into yeast-form cells that colonize immune cells and cause disease. Despite the ability of conidia to initiate infection and disease, they have not been explored on a molecular level. We developed methods to purify H. capsulatum conidia, and we show here that these cells germinate into filaments at room temperature and into yeast-form cells at 37°C. Conidia internalized by macrophages germinate into the yeast form and proliferate within macrophages, ultimately lysing the host cells. Similarly, infection of mice with purified conidia is sufficient to establish infection and yield viable yeast-form cells in vivo. To characterize conidia on a molecular level, we performed whole-genome expression profiling of conidia, yeast, and mycelia from two highly divergent H. capsulatum strains. In parallel, we used homology and protein domain analysis to manually annotate the predicted genes of both strains. Analyses of the resultant data defined sets of transcripts that reflect the unique molecular states of H. capsulatum conidia, yeast, and mycelia. PMID:23563482

  11. Copper and zinc affect the activity of plasma membrane H+-ATPase and thiol content in aquatic fungi.

    PubMed

    Azevedo, M M; Guimarães-Soares, L; Pascoal, C; Cássio, F

    2016-05-01

    Aquatic hyphomycetes are the major microbial decomposers of plant litter in streams. We selected three aquatic hyphomycete species with different abilities to tolerate, adsorb and accumulate copper and zinc, and we investigated the effects of these metals on H+-ATPase activity as well as on the levels of thiol (SH)-containing compounds. Before metal exposure, the species isolated from a metal-polluted stream (Heliscus submersus and Flagellospora curta) had higher levels of thiol compounds than the species isolated from a clean stream (Varicosporium elodeae). However, V. elodeae rapidly increased the levels of thiols after metal exposure, emphasizing the importance of these compounds in fungal survival under metal stress. The highest amounts of metals adsorbed to fungal mycelia were found in the most tolerant species to each metal, i.e. in H. submersus exposed to copper and in V. elodeae exposed to zinc. Short-term (10 min) exposure to copper completely inhibited the activity of H+-ATPase of H. submersus and V. elodeae, whilst zinc only led to a similar effect on H. submersus. However, at longer exposure times (8 days) the most metal-tolerant species exhibited increased H+-ATPase activities, suggesting that the plasma membrane proton pump may be involved in the acclimation of aquatic hyphomycetes to metals. PMID:26916755

  12. Conidial germination in Scedosporium apiospermum, S. aurantiacum, S. minutisporum and Lomentospora prolificans: influence of growth conditions and antifungal susceptibility profiles.

    PubMed

    Mello, Thaís Pereira de; Aor, Ana Carolina; Oliveira, Simone Santiago Carvalho de; Branquinha, Marta Helena; Santos, André Luis Souza Dos

    2016-06-27

    In the present study, we have investigated some growth conditions capable of inducing the conidial germination in Scedosporium apiospermum, S. aurantiacum, S. minutisporum and Lomentospora prolificans. Germination in Sabouraud medium (pH 7.0, 37ºC, 5% CO2) showed to be a typically time-dependent event, reaching ~75% in S. minutisporum and > 90% in S. apiospermum, S. aurantiacum and L. prolificans after 4 h. Similar germination rate was observed when conidia were incubated under different media and pHs. Contrarily, temperature and CO2 tension modulated the germination. The isotropic conidial growth (swelling) and germ tube-like projection were evidenced by microscopy and cytometry. Morphometric parameters augmented in a time-dependent fashion, evidencing changes in size and granularity of fungal cells compared with dormant 0 h conidia. In parallel, a clear increase in the mitochondrial activity was measured during the transformation of conidia-into-germinated conidia. Susceptibility profiles to itraconazole, fluconazole, voriconazole, amphotericin B and caspofungin varied regarding each morphotype and each fungal species. Overall, the minimal inhibitory concentrations for hyphae were higher than conidia and germinated conidia, except for caspofungin. Collectively, our study add new data about the conidia-into-hyphae transformation in Scedosporium and Lomentospora species, which is a relevant biological process of these molds directly connected to their antifungal resistance and pathogenicity mechanisms. PMID:27355215

  13. Pulmonary immune responses to Aspergillus fumigatus in an immunocompetent mouse model of repeated exposures

    PubMed Central

    Buskirk, Amanda D.; Templeton, Steven P.; Nayak, Ajay P.; Hettick, Justin M.; Law, Brandon F.; Green, Brett J.; Beezhold, Donald H.

    2015-01-01

    Aspergillus fumigatus is a filamentous fungus that produces abundant pigmented conidia. Several fungal components have been identified as virulence factors, including melanin; however, the impact of these factors in a repeated exposure model resembling natural environmental exposures remains unknown. This study examined the role of fungal melanin in the stimulation of pulmonary immune responses using immunocompetent BALB/c mice in a multiple exposure model. It compared conidia from wild-type A. fumigatus to two melanin mutants of the same strain, Δarp2 (tan) or Δalb1 (white). Mass spectrometry-based analysis of conidial extracts demonstrated that there was little difference in the protein fingerprint profiles between the three strains. Field emission scanning electron microscopy demonstrated that the immunologically inert Rodlet A layer remained intact in melanin-deficient conidia. Thus, the primary difference between the strains was the extent of melanization. Histopathology indicated that each A. fumigatus strain induced lung inflammation, regardless of the extent of melanization. In mice exposed to Δalb1 conidia, an increase in airway eosinophils and a decrease in neutrophils and CD8+ IL-17+ (Tc17) cells were observed. Additionally, it was shown that melanin mutant conidia were more rapidly cleared from the lungs than wild-type conidia. These data suggest that the presence of fungal melanin may modulate the pulmonary immune response in a mouse model of repeated exposures to A. fumigatus conidia. PMID:23919459

  14. Conidial attachment of metarhizium anisopliae and beauveria bassiana to the larval cuticle of diaprepes abbreviatus (Coleoptera: curculionidae) treated with imidacloprid

    PubMed

    Quintela; McCoy

    1998-11-01

    A series of experiments was conducted to determine the effect of imidacloprid on the number of Metarhizium anisopliae and Beauveria bassiana conidia found on the cuticle of first instar Diaprepes abbreviatus following different treatments. Larvae treated with M. anisopliae conidia and imidacloprid by dipping removed significantly fewer conidia from their cuticle when in contact with soil or a food source compared with fungal-treated larvae alone. In addition, more M. anisopliae and B. bassiana conidia were found on the cuticle of larvae treated with imidacloprid while exposed to soil at 7 and 14% moisture resulting in higher larval mortality and mycosis. Conidial attachment to cuticles of untreated larvae was higher at <1% compared with 7 and 14% soil moistures. M. anisopliae conidia were distributed uniformly over the pleural membrane of the larval cuticle of both untreated and imidacloprid-treated larvae. However, fewer conidia were attached to specific sites such as setae and setal sockets of treated larvae. At 12 h after treatment, imidacloprid-treated larvae had fewer conidia removed from exposed cuticle, setae, and spiracles than did untreated larvae. Cuticular exposure to imidacloprid at doses >0.01% (AI) affected conidial attachment of M. anisopliae negatively. Conidial number decreased sevenfold at 0.1% (AI). Comparative data on the effect of imidacloprid formulation on conidial attachment showed that components of the inert ingredient were responsible for lower conidial attachment on larval cuticle at higher insecticidal doses. Copyright 1998 Academic Press. PMID:9784344

  15. Pulmonary immune responses to Aspergillus fumigatus in an immunocompetent mouse model of repeated exposures.

    PubMed

    Buskirk, Amanda D; Templeton, Steven P; Nayak, Ajay P; Hettick, Justin M; Law, Brandon F; Green, Brett J; Beezhold, Donald H

    2014-01-01

    Aspergillus fumigatus is a filamentous fungus that produces abundant pigmented conidia. Several fungal components have been identified as virulence factors, including melanin; however, the impact of these factors in a repeated exposure model resembling natural environmental exposures remains unknown. This study examined the role of fungal melanin in the stimulation of pulmonary immune responses using immunocompetent BALB/c mice in a multiple exposure model. It compared conidia from wild-type A. fumigatus to two melanin mutants of the same strain, Δarp2 (tan) or Δalb1 (white). Mass spectrometry-based analysis of conidial extracts demonstrated that there was little difference in the protein fingerprint profiles between the three strains. Field emission scanning electron microscopy demonstrated that the immunologically inert Rodlet A layer remained intact in melanin-deficient conidia. Thus, the primary difference between the strains was the extent of melanization. Histopathology indicated that each A. fumigatus strain induced lung inflammation, regardless of the extent of melanization. In mice exposed to Δalb1 conidia, an increase in airway eosinophils and a decrease in neutrophils and CD8(+) IL-17(+) (Tc17) cells were observed. Additionally, it was shown that melanin mutant conidia were more rapidly cleared from the lungs than wild-type conidia. These data suggest that the presence of fungal melanin may modulate the pulmonary immune response in a mouse model of repeated exposures to A. fumigatus conidia. PMID:23919459

  16. Abundant Respirable Ergot Alkaloids from the Common Airborne Fungus Aspergillus fumigatus†

    PubMed Central

    Panaccione, Daniel G.; Coyle, Christine M.

    2005-01-01

    Ergot alkaloids are mycotoxins that interact with several monoamine receptors, negatively affecting cardiovascular, nervous, reproductive, and immune systems of exposed humans and animals. Aspergillus fumigatus, a common airborne fungus and opportunistic human pathogen, can produce ergot alkaloids in broth culture. The objectives of this study were to determine if A. fumigatus accumulates ergot alkaloids in a respirable form in or on its conidia, to quantify ergot alkaloids associated with conidia produced on several different substrates, and to measure relevant physical properties of the conidia. We found at least four ergot alkaloids, fumigaclavine C, festuclavine, fumigaclavine A, and fumigaclavine B (in order of abundance), associated with conidia of A. fumigatus. Under environmentally relevant conditions, the total mass of ergot alkaloids often constituted >1% of the mass of the conidium. Ergot alkaloids were extracted from conidia produced on all media tested, and the greatest quantities were observed when the fungus was cultured on latex paint or cultured maize seedlings. The values for physical properties of conidia likely to affect their respirability (i.e., diameter, mass, and specific gravity) were significantly lower for A. fumigatus than for Aspergillus nidulans, Aspergillus niger, and Stachybotrys chartarum. The demonstration of relatively high concentrations of ergot alkaloids associated with conidia of A. fumigatus presents opportunities for investigations of potential contributions of the toxins to adverse health effects associated with the fungus and to aspects of the biology of the fungus that contribute to its success. PMID:15933008

  17. Abundant respirable ergot alkaloids from the common airborne fungus Aspergillus fumigatus.

    PubMed

    Panaccione, Daniel G; Coyle, Christine M

    2005-06-01

    Ergot alkaloids are mycotoxins that interact with several monoamine receptors, negatively affecting cardiovascular, nervous, reproductive, and immune systems of exposed humans and animals. Aspergillus fumigatus, a common airborne fungus and opportunistic human pathogen, can produce ergot alkaloids in broth culture. The objectives of this study were to determine if A. fumigatus accumulates ergot alkaloids in a respirable form in or on its conidia, to quantify ergot alkaloids associated with conidia produced on several different substrates, and to measure relevant physical properties of the conidia. We found at least four ergot alkaloids, fumigaclavine C, festuclavine, fumigaclavine A, and fumigaclavine B (in order of abundance), associated with conidia of A. fumigatus. Under environmentally relevant conditions, the total mass of ergot alkaloids often constituted >1% of the mass of the conidium. Ergot alkaloids were extracted from conidia produced on all media tested, and the greatest quantities were observed when the fungus was cultured on latex paint or cultured maize seedlings. The values for physical properties of conidia likely to affect their respirability (i.e., diameter, mass, and specific gravity) were significantly lower for A. fumigatus than for Aspergillus nidulans, Aspergillus niger, and Stachybotrys chartarum. The demonstration of relatively high concentrations of ergot alkaloids associated with conidia of A. fumigatus presents opportunities for investigations of potential contributions of the toxins to adverse health effects associated with the fungus and to aspects of the biology of the fungus that contribute to its success. PMID:15933008

  18. Conidial germination in Scedosporium apiospermum, S. aurantiacum, S. minutisporum and Lomentospora prolificans: influence of growth conditions and antifungal susceptibility profiles

    PubMed Central

    de Mello, Thaís Pereira; Aor, Ana Carolina; de Oliveira, Simone Santiago Carvalho; Branquinha, Marta Helena; dos Santos, André Luis Souza

    2016-01-01

    In the present study, we have investigated some growth conditions capable of inducing the conidial germination in Scedosporium apiospermum, S. aurantiacum, S. minutisporum and Lomentospora prolificans. Germination in Sabouraud medium (pH 7.0, 37ºC, 5% CO2) showed to be a typically time-dependent event, reaching ~75% in S. minutisporum and > 90% in S. apiospermum, S. aurantiacum and L. prolificans after 4 h. Similar germination rate was observed when conidia were incubated under different media and pHs. Contrarily, temperature and CO2 tension modulated the germination. The isotropic conidial growth (swelling) and germ tube-like projection were evidenced by microscopy and cytometry. Morphometric parameters augmented in a time-dependent fashion, evidencing changes in size and granularity of fungal cells compared with dormant 0 h conidia. In parallel, a clear increase in the mitochondrial activity was measured during the transformation of conidia-into-germinated conidia. Susceptibility profiles to itraconazole, fluconazole, voriconazole, amphotericin B and caspofungin varied regarding each morphotype and each fungal species. Overall, the minimal inhibitory concentrations for hyphae were higher than conidia and germinated conidia, except for caspofungin. Collectively, our study add new data about the conidia-into-hyphae transformation in Scedosporium and Lomentospora species, which is a relevant biological process of these molds directly connected to their antifungal resistance and pathogenicity mechanisms. PMID:27355215

  19. Hide, Keep Quiet, and Keep Low: Properties That Make Aspergillus fumigatus a Successful Lung Pathogen

    PubMed Central

    Escobar, Natalia; Ordonez, Soledad R.; Wösten, Han A. B.; Haas, Pieter-Jan A.; de Cock, Hans; Haagsman, Henk P.

    2016-01-01

    Representatives of the genus Aspergillus are opportunistic fungal pathogens. Their conidia can reach the alveoli by inhalation and can give rise to infections in immunocompromised individuals. Aspergillus fumigatus is the causal agent of invasive aspergillosis in nearly 90% of the cases. It is not yet well-established what makes this fungus more pathogenic than other aspergilli such as A. niger. Here, we show that A. fumigatus and A. niger conidia adhere with similar efficiency to lung epithelial A549 cells but A. fumigatus conidia internalized 17% more efficiently. Conidia of both aspergilli were taken up in phagolysosomes 8 h after the challenge. These organelles only acidified in the case of A. niger, which is probably due to the type of melanin coating of the conidia. Viability of both types of conidia was not affected after uptake in the phagolysosomes. Germination of A. fumigatus and A. niger conidia in the presence of epithelial cells was delayed when compared to conidia in the medium. However, germination of A. niger conidia was still higher than that of A. fumigatus 10 h after exposure to A549 cells. Remarkably, A. fumigatus hyphae grew mainly parallel to the epithelium, while growth direction of A. niger hyphae was predominantly perpendicular to the plane of the cells. Neutrophils reduced germination and hyphal growth of A. niger, but not of A fumigatus, in presence of epithelial cells. Taken together, efficient internalization, delayed germination, and hyphal growth parallel to the epithelium gives a new insight into what could be the causes for the success of A. fumigatus compared to A. niger as an opportunistic pathogen in the lung. PMID:27092115

  20. Comparison between superficial and solid-state cultures of Isaria fumosorosea: conidial yields, quality and sensitivity to oxidant conditions.

    PubMed

    Muñiz-Paredes, Facundo; Garza-López, Paul Misael; Viniegra-González, Gustavo; Loera, Octavio

    2016-07-01

    Conidia production and quality from mycoinsecticides in solid-state cultures (SSC) are frequently inferred from superficial culture (SC) results. Both parameters were evaluated for two Isaria fumosorosea strains (ARSEF 3302 and CNRCB1), in SC and SSC, using culture media with the same chemical composition. For both strains, conidia production was higher in SC than SSC in terms of conidia per gram of dry substrate. Germination in both strains did not show significant differences between SC and SSC (>90 %). Similarly, conidia viability in ARSEF 3302 strain did not show differences at early stages between SC and SSC, but was higher in SC compared to SSC in the late stage of culture; in contrast, conidia from CNRCB1 strain did not differ between both culture systems. Some infectivity parameters improved in conidia from SSC, compared to SC at the early stages, but these differences disappeared at the final stage, independently of the strain. Both strains showed decreased conidia production when 26 % O2 pulses were applied; nevertheless, conidiation in SSC was two orders of magnitude more sensitive to oxidant pulses. In SC with 26 % O2 pulses, conidia viability for both strains at early stages, was higher than in normal atmospheric conditions. Infectivity towards Galleria mellonella larvae was similar between conidia from normal atmosphere and oxidant conditions; notably, for the strain ARSEF 3302 infectivity decreased at the final stage. This study shows the intrinsic differences between SC and SSC, which should be considered when using SC as a model to design production processes in SSC. PMID:27263006

  1. Insight into the feeding behavior of predatory mites on Beauveria bassiana, an arthropod pathogen.

    PubMed

    Wu, Shengyong; Zhang, Ye; Xu, Xuenong; Lei, Zhongren

    2016-01-01

    Interactions between fungal entomopathogens and pest predators are particularly relevant in control of agricultural insect pests. In a laboratory study, we confirmed that the predatory mite, Neoseiulus barkeri, exhibited feeding behavior on the entomopathogenic fungus Beauveria bassiana conidia through DNA extracts. Using transmission electron microscopy, we determined that the majority of conidia found in the mite gut tended to dissolve within 24 h post ingestion, suggesting that the conidia had probably lost their viability. To our knowledge this is the first report of feeding behavior of phytoseiid mites on entomopathogenic fungus. The findings expand our knowledge of fungus-predator interactions. PMID:27041703

  2. Insight into the feeding behavior of predatory mites on Beauveria bassiana, an arthropod pathogen

    PubMed Central

    Wu, Shengyong; Zhang, Ye; Xu, Xuenong; Lei, Zhongren

    2016-01-01

    Interactions between fungal entomopathogens and pest predators are particularly relevant in control of agricultural insect pests. In a laboratory study, we confirmed that the predatory mite, Neoseiulus barkeri, exhibited feeding behavior on the entomopathogenic fungus Beauveria bassiana conidia through DNA extracts. Using transmission electron microscopy, we determined that the majority of conidia found in the mite gut tended to dissolve within 24 h post ingestion, suggesting that the conidia had probably lost their viability. To our knowledge this is the first report of feeding behavior of phytoseiid mites on entomopathogenic fungus. The findings expand our knowledge of fungus–predator interactions. PMID:27041703

  3. Differential allergy responses to Metarhizium anisopliae fungal component extracts in BALB/c mice

    EPA Science Inventory

    Intratracheal aspiration (IA) exposure to Metarhizium anisopliae crude antigen (MACA), which is composed of equal protein amounts of mycelium (MYC), conidia (CON) and inducible proteases/chitinases (IND) extracts/filtrates, has resulted in responses characteristic of human allerg...

  4. PREPARATION AND REGENERATION OF PROTOPLASTS OF COLLETOTRICHUM GLEOSPORIODES F. SP. AESCHYNOMENE

    EPA Science Inventory

    Protoplasts were produced from conidia of Colletotrichum gloesporioides f. sp. aeschynomene, a fungal plant pathogen of Aeschynomene virginica, during treatment with Novozym 234 or a mixture of chitinase and B-glucuronidase after pretreatment with 2-mercaptoethanol. rotoplasts we...

  5. DIFFERENTIAL ALLERGIC AND NEUROTROPHIN RESPONSES TO FUNGAL COMPONENT EXTRACTS IN BALB/C MICE

    EPA Science Inventory

    Metarhizium anisopliae mycelium (MYC), conidia (CON) and inducible protease (IND) extracts were combined to produce the antigen MACA to screen for allergenic potential. Involuntary aspiration (IA) exposure to MACA in BALB/c mice has caused immune, inflammatory and physiological ...

  6. Entomopathogenic Fungus as a Biological Control for an Important Vector of Livestock Disease: The Culicoides Biting Midge

    PubMed Central

    Ansari, Minshad Ali; Pope, Edward C.; Carpenter, Simon; Scholte, Ernst-Jan; Butt, Tariq M.

    2011-01-01

    Background The recent outbreak of bluetongue virus in northern Europe has led to an urgent need to identify control measures for the Culicoides (Diptera: Ceratopogonidae) biting midges that transmit it. Following successful use of the entomopathogenic fungus Metarhizium anisopliae against larval stages of biting midge Culicoides nubeculosus Meigen, we investigated the efficacy of this strain and other fungi (Beauveria bassiana, Isaria fumosorosea and Lecanicillium longisporum) as biocontrol agents against adult C. nubeculosus in laboratory and greenhouse studies. Methodology/Findings Exposure of midges to ‘dry’ conidia of all fungal isolates caused significant reductions in survival compared to untreated controls. Metarhizium anisopliae strain V275 was the most virulent, causing a significantly decrease in midge survival compared to all other fungal strains tested. The LT50 value for strain V275 was 1.42 days compared to 2.21–3.22 days for the other isolates. The virulence of this strain was then further evaluated by exposing C. nubeculosus to varying doses (108–1011 conidia m−2) using different substrates (horse manure, damp peat, leaf litter) as a resting site. All exposed adults were found to be infected with the strain V275 four days after exposure. A further study exposed C. nubeculosus adults to ‘dry’ conidia and ‘wet’ conidia (conidia suspended in 0.03% aq. Tween 80) of strain V275 applied to damp peat and leaf litter in cages within a greenhouse. ‘Dry’ conidia were more effective than ‘wet’ conidia, causing 100% mortality after 5 days. Conclusion/Significance This is the first study to demonstrate that entomopathogenic fungi are potential biocontrol agents against adult Culicoides, through the application of ‘dry’ conidia on surfaces (e.g., manure, leaf litter, livestock) where the midges tend to rest. Subsequent conidial transmission between males and females may cause an increased level of fungi-induced mortality in midges

  7. Horizontal Transmission of Metarhizium anisopliae in Fruit Flies and Effect of Fungal Infection on Egg Laying and Fertility

    PubMed Central

    Dimbi, Susan; Maniania, Nguya K.; Ekesi, Sunday

    2013-01-01

    Fly-to-fly transmission of conidia of the entomopathogenic fungus Metarhizium anisopliae and the effect of fungal infection on the reproductive potential of females surviving infection were investigated in three fruit fly species, Ceratitis cosyra, C. fasciventris, and C. capitata. The number of conidia picked up by a single fruit fly was determined in C. cosyra. The initial uptake (Day 0) of conidia by a single fly was approx. 1.1 × 106 conidia after exposure to the treated substrate. However, the number of conidia dropped from 7.2 × 105 to 4.1 × 105 conidia after 2 and 8 h post-exposure, respectively. The number of conidia picked up by a single fungus-treated fly (“donor”) varied between 3.8 × 105 and 1.0 × 106 in the three fruit fly species, resulting in 100% mortality 5–6 days post-exposure. When fungus-free flies of both sexes (“recipient” flies) were allowed to mate with “donor” flies, the number of conidia picked up by a single fly varied between 1.0 × 105 and 2.5 × 105, resulting in a mortality of 83–100% in C. capitata, 72–85% in C. cosyra and 71–93% in C. fasciventris 10–15 days post-inoculation. There was an effect of fungal infection on female egg laying in the three species of fruit flies as control flies laid more eggs than fungus-treated females. The percentage reduction in fecundity in flies infected with M. anisopliae was 82, 73 and 37% in C. capitata, C. fasciventris and C. cosyra, respectively. The results are discussed with regard to application in autodissemination techniques. PMID:26464386

  8. Germination-defective mutant of Neurospora crassa that responds to siderophores

    NASA Technical Reports Server (NTRS)

    Charlang, G.; Williams, N. P.

    1977-01-01

    A conditionally germination-defective mutant of Neurospora crassa has been found to be partially curable by ferricrocin and other siderophores. The mutant conidia rapidly lose their membrane-bound siderophores when suspended in buffer or growth media. Germination is consequently delayed unless large numbers of conidia are present (positive population effect). This indicates that the mutant has a membrane defect involving the siderophore attachment site.

  9. Adulticidal and larvicidal activity of Beauveria bassiana and Metarhizium anisopliae against housefly, Musca domestica (Diptera: Muscidae), in laboratory and simulated field bioassays.

    PubMed

    Mishra, Sapna; Kumar, Peeyush; Malik, Anushree; Satya, Santosh

    2011-06-01

    The susceptibility of the adult and larval stage of housefly, Musca domestica L. (Diptera: Muscidae), to two entomopathogenic fungi, Metarhizium anisopliae (Metsch.) Sor. and Beauveria bassiana (Bals.) Vuill., was evaluated under laboratory and simulated field bioassays. Bioassays on adult houseflies were carried out at different conidial concentrations ranging from 10(3) to 10(9) conidia/ml in petri plate and minichamber assays. Absolute mortality was observed within 4-5 days at all the concentrations tested. M. anisopliae was found to be more effective with LC(50) of 6.75 × 10(7) conidia/ml compared with 1.21 × 10(8) conidia/ml of B. bassiana in petri plate bioassay. Similar trend was observed in minichamber bioassay. Larvicidal activity evaluated through petri plate bioassay also indicated that M. anisopliae was more effective larvicide with LC(50) of 4.1 × 10(8) conidia/ml as against 3.31 × 10(9) conidia/ml of B. bassiana. Larvicidal activity was further evaluated in simulated field condition of decaying waste matrix using dry conidial formulations (10(8) conidia/g) of both the fungi. Larval mortality obtained in this assay was 43% (B. bassiana) and 63% (M. anisopliae). Remarkably better performance of M. anisopliae as an adulticidal and larvicidal agent over B. bassiana in laboratory bioassays as well as simulated field conditions suggests that it may have good potential to become part of an integrated housefly control program. PMID:21161273

  10. Neurospora crassa 1,3-α-glucan synthase, AGS-1, is required for cell wall biosynthesis during macroconidia development

    PubMed Central

    Fu, Ci; Tanaka, Asuma

    2014-01-01

    The Neurospora crassa genome encodes two 1,3-α-glucan synthases. One of these 1,3-α-glucan synthase genes, ags-1, was shown to be required for the synthesis of 1,3-α-glucan in the aerial hyphae and macroconidia cell walls. 1,3-α-Glucan was found in the conidia cell wall, but was absent from the vegetative hyphae cell wall. Deletion of ags-1 affected conidial development. Δags-1 produced only 5 % as many conidia as the WT and most of the conidia produced by Δags-1 were not viable. The ags-1 upstream regulatory elements were shown to direct cell-type-specific expression of red fluorescent protein in conidia and aerial hyphae. A haemagglutinin-tagged AGS-1 was found to be expressed in aerial hyphae and conidia. The research showed that 1,3-α-glucan is an aerial hyphae and conidia cell wall component, and is required for normal conidial differentiation. PMID:24847001

  11. In Vitro Photodynamic Inactivation of Plant-Pathogenic Fungi Colletotrichum acutatum and Colletotrichum gloeosporioides with Novel Phenothiazinium Photosensitizers

    PubMed Central

    de Menezes, Henrique D.; Rodrigues, Gabriela B.; Teixeira, Simone de Pádua; Massola, Nelson S.; Bachmann, Luciano; Wainwright, Mark

    2014-01-01

    The increasing tolerance to currently used fungicides in both clinical and agricultural areas is of great concern. The nonconventional light-based approach of antimicrobial photodynamic treatment (APDT) is a promising alternative to conventional fungicides. We evaluated the effects of APDT with four phenothiazinium derivatives (methylene blue [MB], new methylene blue N [NMBN], toluidine blue O [TBO], and the novel pentacyclic phenothiazinium photosensitizer [PS] S137) on conidia of three fungal species (Colletotrichum acutatum, Colletotrichum gloeosporioides, and Aspergillus nidulans). The efficacy of APDT with each PS was determined, initially, based on photosensitizer MICs. Additionally, the effects of APDT with two selected PSs (NMBN and S137) on survival of conidia were evaluated. The subcellular localization of the PS in C. acutatum conidia was determined. The effects of photodynamic treatments on leaves of the plant host Citrus sinensis were also investigated. APDT with S137 showed the lowest MIC. MICs for S137 were 5 μM for the three fungal species when a fluence of 25 J cm−2 was used. APDT with NMBN (50 μM) and S137 (10 μM) resulted in a reduction in the survival of the conidia of all species of approximately 5 logs with fluences of ≥15 J cm−2. Washing of the conidia before light exposure did not prevent photodynamic inactivation. Both NMBN and S137 accumulated in cytoplasmic structures, such as lipid bodies, of C. acutatum conidia. No damage to orange tree leaves was observed after APDT. PMID:24362436

  12. Rapid detection of aflatoxin producing fungi in food by real-time quantitative loop-mediated isothermal amplification.

    PubMed

    Luo, Jie; Vogel, Rudi F; Niessen, Ludwig

    2014-12-01

    Aflatoxins represent a serious risk for human and animal health. They are mainly produced by Aspergillus flavus and Aspergillus parasiticus but also by Aspergillus nomius. Three species specific turbidimeter based real-time LAMP (loop-mediated isothermal amplification) assays were developed to quantify the three species individually in conidial solutions and to define contamination levels in samples of shelled Brazil nuts, maize, and peanuts. Standard curves relating spore numbers to time to threshold (Tt) values were set up for each of the species. Assays had detection limits of 10, 100 and 100 conidia per reaction of A. flavus, A. parasiticus, and A. nomius, respectively. Analysis of contaminated sample materials revealed that the A. nomius specific real-time LAMP assay detected a minimum of 10 conidia/g in Brazil nuts while assays specific for A. flavus and A. parasiticus had detection limits of 10(2) conidia/g and 10(5) conidia/g, respectively in peanut samples as well as 10(4) conidia/g and 10(4) conidia/g, respectively in samples of maize. The real-time LAMP assays developed here appear to be promising tools for the prediction of potential aflatoxigenic risk at an early stage and in all critical control points of the food and feed production chain. PMID:25084656

  13. Development of a submerged-liquid sporulation medium for the johnsongrass bioherbicide Gloeocercospora sorghi.

    PubMed

    Mitchell, James K; Njalamimba-Bertsch, Mushoba; Bradford, Nathan R; Birdsong, Julie A

    2003-10-01

    Submerged culture experiments were conducted in three phases to determine the optimal medium for rapidly producing conidia of the fungal bioherbicide Gloeocercospora sorghi. In phase I, 18 crude carbon sources were evaluated to determine which would support sporulation. Under the conditions tested, butter bean and lima bean brines (1.5-4.6 mS/cm) provided best conidiation. In phase II, a fractional-factorial design was utilized to screen 76 different medium adjuncts in combination with butter bean brine for improved sporulation. d-Mannitol and carboxymethylcellulose (CMC) were the only acceptable factors that resulted in a significant improvement. In phase III, a central composite design with response surface methodology was used to optimize concentrations of these critical factors. The model predicted optimal sporulation in a medium composed of 2.69 mS/cm butter bean brine +0.043 M d-mannitol +0.37% w/v CMC with an expected titer of 1.51x10(7) conidia/ml. Actual mean titer attained with the model-derived medium was 1.91x10(7) conidia/ml. Optimal sporulation occurred at 25.5 degrees C in this medium and conidia remained viable up to 2.71 days when stored at 12 degrees C. No significant difference was observed in virulence of conidia produced on agar vs washed conidia produced in the model-derived (liquid) medium. PMID:14530913

  14. The RodA hydrophobin on Aspergillus fumigatus spores masks Dectin-1 and Dectin-2 dependent responses and enhances fungal survival in vivo

    PubMed Central

    de Jesus Carrion, Steven; Leal, Sixto M.; Ghannoum, Mahmoud A.; Pearlman, Eric

    2014-01-01

    Aspergillus and Fusarium species are important causes of fungal infections worldwide. Airborne spores (conidia) of these filamentous fungi express a surface protein that confers hydrophobicity (hydrophobin), and which covers cell wall components that would otherwise induce a host immune cell response. Using a mutant Aspergillus fumigatus strain that does not express the RodA hydrophobin (ΔrodA), and Aspergillus and Fusarium conidia from clinical isolates that were treated with hydrofluoric acid (HF, which removes the A. fumigatus RodA protein), we observed increased surface exposure of β1,3-glucan and α-mannose on Aspergillus and Fusarium conidia. We also found that ΔrodA and HF treated conidia stimulate significantly higher NF-κB p65 nuclear translocation and cytokine production by macrophages from C57BL/6, but not from Dectin-1−/− or Dectin-2−/− mice. Using a murine model of A. fumigatus corneal infection, we found that ΔrodA conidia exhibited increased cytokine production, neutrophil infiltration, and more rapid fungal clearance from C57BL/6 corneas compared with the parent G10 strain, which was dependent on Dectin-1 and Dectin-2. Together, these findings identify the hydrophobin RodA as a virulence factor that masks Dectin-1 and Dectin-2 recognition of conidia, resulting in impaired neutrophil recruitment to the cornea and increased fungal survival and clinical disease. PMID:23926321

  15. In vitro photodynamic inactivation of plant-pathogenic fungi Colletotrichum acutatum and Colletotrichum gloeosporioides with Novel Phenothiazinium photosensitizers.

    PubMed

    de Menezes, Henrique D; Rodrigues, Gabriela B; Teixeira, Simone de Pádua; Massola, Nelson S; Bachmann, Luciano; Wainwright, Mark; Braga, Gilberto U L

    2014-03-01

    The increasing tolerance to currently used fungicides in both clinical and agricultural areas is of great concern. The nonconventional light-based approach of antimicrobial photodynamic treatment (APDT) is a promising alternative to conventional fungicides. We evaluated the effects of APDT with four phenothiazinium derivatives (methylene blue [MB], new methylene blue N [NMBN], toluidine blue O [TBO], and the novel pentacyclic phenothiazinium photosensitizer [PS] S137) on conidia of three fungal species (Colletotrichum acutatum, Colletotrichum gloeosporioides, and Aspergillus nidulans). The efficacy of APDT with each PS was determined, initially, based on photosensitizer MICs. Additionally, the effects of APDT with two selected PSs (NMBN and S137) on survival of conidia were evaluated. The subcellular localization of the PS in C. acutatum conidia was determined. The effects of photodynamic treatments on leaves of the plant host Citrus sinensis were also investigated. APDT with S137 showed the lowest MIC. MICs for S137 were 5 μM for the three fungal species when a fluence of 25 J cm(-2) was used. APDT with NMBN (50 μM) and S137 (10 μM) resulted in a reduction in the survival of the conidia of all species of approximately 5 logs with fluences of ≥15 J cm(-2). Washing of the conidia before light exposure did not prevent photodynamic inactivation. Both NMBN and S137 accumulated in cytoplasmic structures, such as lipid bodies, of C. acutatum conidia. No damage to orange tree leaves was observed after APDT. PMID:24362436

  16. First report of Veronaea botryosa as a causal agent of chromomycosis in frogs.

    PubMed

    Hosoya, Tsuyoshi; Hanafusa, Yasuko; Kudo, Tomoo; Tamukai, Kenichi; Une, Yumi

    2015-05-01

    A dematiaceous hyphomycete, isolated from frogs, was determined as the possible etiologic agent of a case of systemic chromomycosis this cold-blooded animal. The fungus was identified as Veronaea botryosa on the basis of morphological features observed in histopathological examination and molecular phylogenetic evidence. Although V. botryosa is known to be distributed widely in litter and as a human pathogen, this is the first confirmed report of its involvement in a lethal infection in a cold-blooded animal, including an anuran. PMID:25851263

  17. Dendryphion penicillatum and Pleospora papaveracea, Destructive Seedborne Pathogens and Potential Mycoherbicides for Papaver somniferum.

    PubMed

    O'Neill, N R; Jennings, J C; Bailey, B A; Farr, D F

    2000-07-01

    ABSTRACT Dendryphion penicillatum and Pleospora papaveracea were isolated from blighted Papaver somniferum and Papaver bracteatum plants grown in growth chambers and the field in Beltsville, MD. The etiology of the diseases was determined, and the fungi are being investigated as potential mycoherbicides to control the narcotic opium poppy plant. P. papaveracea is known to be a highly destructive seedborne pathogen of Papaver somniferum, causing seedling blight, leaf blight, crown rot, and capsule rot. Single conidia and ascospores were isolated and cultures established from naturally infested seed and diseased foliage and pods of opium poppy from Iran, Colombia, Venezuela, Sweden, India, and the United States (Maryland and Washington). Mycelia and conidia of P. papaveracea and D. penicillatum produced on necrotic leaf tissues appear morphologically similar, and the fungi were previously considered to be anamorph and teleomorph. However, no anamorph/teleomorph connection could be established, and the fungi appear to be distinct taxa. P. papaveracea produced conidia, mature pseudothecia, and chlamydospores in vitro and on infected stems. D. penicillatum produced conidia, microsclerotia, and macronematous conidiophores. Although both fungi were pathogenic to three poppy cultivars, conidial inoculum from P. papaveracea cultures was more virulent than conidial inoculum from D. penicillatum. Eight-week-old plants became necrotic and died 8 days after inoculation with a conidial suspension of P. papaveracea at 2 x 10(5) spores per ml. Disease severity was significantly enhanced by inoculum formulations that contained corn oil, by higher conidial inoculum concentrations, and by increased wetness periods. Symptoms on plants inoculated with either pathogen included leaf and stem necrosis, stem girdling, stunting, necrotic leaf spots, and foliar and pod blight. Inoculated seedlings exhibited wire stem, damping-off, and root rot. Conidia, and less frequently pseudothecia, of P

  18. Tools for delivering entomopathogenic fungi to malaria mosquitoes: effects of delivery surfaces on fungal efficacy and persistence

    PubMed Central

    2010-01-01

    Background Entomopathogenic fungi infection on malaria vectors increases daily mortality rates and thus represents a control measure that could be used in integrated programmes alongside insecticide-treated bed nets (ITNs) and indoor residual spraying (IRS). Before entomopathogenic fungi can be integrated into control programmes, an effective delivery system must be developed. Methods The efficacy of Metarhizium anisopliae ICIPE-30 and Beauveria bassiana I93-825 (IMI 391510) (2 × 1010 conidia m-2) applied on mud panels (simulating walls of traditional Tanzanian houses), black cotton cloth and polyester netting was evaluated against adult Anopheles gambiae sensu stricto. Mosquitoes were exposed to the treated surfaces 2, 14 and 28 d after conidia were applied. Survival of mosquitoes was monitored daily. Results All fungal treatments caused a significantly increased mortality in the exposed mosquitoes, descending with time since fungal application. Mosquitoes exposed to M. anisopliae conidia on mud panels had a greater daily risk of dying compared to those exposed to conidia on either netting or cotton cloth (p < 0.001). Mosquitoes exposed to B. bassiana conidia on mud panels or cotton cloth had similar daily risk of death (p = 0.14), and a higher risk than those exposed to treated polyester netting (p < 0.001). Residual activity of fungi declined over time; however, conidia remained pathogenic at 28 d post application, and were able to infect and kill 73 - 82% of mosquitoes within 14 d. Conclusion Both fungal isolates reduced mosquito survival on immediate exposure and up to 28 d after application. Conidia were more effective when applied on mud panels and cotton cloth compared with polyester netting. Cotton cloth and mud, therefore, represent potential substrates for delivering fungi to mosquitoes in the field. PMID:20799967

  19. The interaction between Helminthosporium carbonum and maize: Induced resistance and the role of an inhibitor

    SciTech Connect

    Cantone, F.A.

    1989-01-01

    Helminthosporium carbonum race 1 produces large, necrotic lesions on susceptible leaves of maize, whereas race 2 causes small, chlorotic flecks. Resistance to race 1 on susceptible leaves was induced when race 2 was inoculated for at least 10 h prior to a challenge inoculation with the pathogen and was manifest as a decrease in the number of appressoria and reduced penetration by race 1 conidia. Induced resistance was prevented or reversed when HC-toxin was added to challenge race 1 inoculum. The basis for protection appears to be a volatile, inhibitory compound produced by the host. This inhibitor was always associated with treatments that resulted in resistance, whereas no inhibitory activity was detected in diffusates from susceptible reactions. The appearance of inhibitor in diffusates coincided with the appearance of protection on the leaf. In addition to race 2 of H. carbonum, other fungi (H. victoriae, H. turcicum, and Alternaria) also induced production of the inhibitor as well as resistance to race 1. The inhibitor prevented the germination of conidia of all fungi tested. The growth of two phytopathogenic bacteria was also completely inhibited. Incorporation of {sup 3}H-leucine and {sup 14}C-uridine into protein and RNA, respectively, by conidia of H. carbonum was prevented within 15 min of exposure to inhibitor. In addition, respiration of conidia in inhibitor was reduced within 90 min to just 25% of the rate of conidia germinated in water. However, inhibitory activity of the diffusates was readily reversed when conidia were rinsed with water or when organic or amino acids were added to inhibited conidia. The addition of sodium acetate to race 2 and race 1 inocula resulted in lesion enlargement and also nullified inhibitory activity in vitro.

  20. Effects of passages through a suitable host of the fungus, Metarhizium anisopliae, on the virulence of acaricide- susceptible and resistant strains of the tick, Rhipicephalus microplus

    PubMed Central

    Adames, Markis; Fernández-Ruvalcaba, Manuel; Peña-Chora, Guadalupe; Hernández-Velázquez, Victor M.

    2011-01-01

    The aim of this work was to assess the virulence of strain M379 of the fungus, Metarhizium anisopliae (Metchnikoff) Sorokin (Hypocreales: Clavicipitaceae) after different passages through a suitable host and at different concentrations for the control of both acaricide-susceptible and resistant strains of the tick, Rhipicephalus (formerly Boophilus) microplus Canestrini (Ixodida: Ixodidae) in vitro. The highest value of LC50 for the susceptible strain corresponded to zero passage with 7.68 × 107 conidia/ml followed by the fourth passage with 2.68 × 107, which reduced 2.87-fold the lethal concentration. When comparing LC50 values of the fourth vs. the seventh passage (2.59 × 105 conidia/ml), the lethal concentration was reduced 103.47-fold by the seventh passage. In addition, in the resistant strain the LC50 highest value corresponded to zero passage with 4.95 × 107 conidia/ml followed by the fourth passage with 7.86 × 106, which reduced 6.30-fold the lethal concentration. When comparing LC50 values of the fourth vs. the seventh passage (1.04 × 105 conidia/ml) in the resistant strain, the lethal concentration was reduced 75.58-fold by the seventh passage. These results suggest that the number of passages on M. anisopliae through a suitable host increased its virulence on both R microplus strains. When comparing LC50 of the zero passage through a suitable host of both acaricide-susceptible and resistant strains, the highest LC50 values corresponded to the susceptible strain with 7.68 × 107 conidia/ml followed by the resistant one with 4.95 × 107, showing that on the resistant strain the lethal concentration is reduced by 1.55-fold. When comparing the fourth passage, the highest values of LC50 corresponded to the susceptible strain with 2.68 × 107 conidia/ml followed by the resistant one with 7.86 × 106 conidia/ml, showing for the resistant strain a 3.41-fold reduced lethal concentration. Moreover, when comparing the seventh passages, the highest values of

  1. Inactivation of plant-pathogenic fungus Colletotrichum acutatum with natural plant-produced photosensitizers under solar radiation.

    PubMed

    Fracarolli, Letícia; Rodrigues, Gabriela B; Pereira, Ana C; Massola Júnior, Nelson S; Silva-Junior, Geraldo José; Bachmann, Luciano; Wainwright, Mark; Bastos, Jairo Kenupp; Braga, Gilberto U L

    2016-09-01

    The increasing tolerance to currently used fungicides and the need for environmentally friendly antimicrobial approaches have stimulated the development of novel strategies to control plant-pathogenic fungi such as antimicrobial phototreatment (APT). We investigated the in vitro APT of the plant-pathogenic fungus Colletotrichum acutatum with furocoumarins and coumarins and solar radiation. The compounds used were: furocoumarins 8-methoxypsoralen (8-MOP) and 5,8-dimethoxypsoralen (isopimpinellin), coumarins 2H-chromen-2-one (coumarin), 7-hydroxycoumarin, 5,7-dimethoxycoumarin (citropten) and a mixture (3:1) of 7-methoxycoumarin and 5,7-dimethoxycoumarin. APT of conidia with crude extracts from 'Tahiti' acid lime, red and white grapefruit were also performed. Pure compounds were tested at 50μM concentration and mixtures and extracts at 12.5mgL(-1). The C. acutatum conidia suspension with or without the compounds was exposed to solar radiation for 1h. In addition, the effects of APT on the leaves of the plant host Citrus sinensis were determined. APT with 8-MOP was the most effective treatment, killing 100% of the conidia followed by the mixture of two coumarins and isopimpinellin that killed 99% and 64% of the conidia, respectively. APT with the extracts killed from 20% to 70% of the conidia, and the extract from 'Tahiti' lime was the most effective. No damage to sweet orange leaves was observed after APT with any of the compounds or extracts. PMID:27434699

  2. Conidial germination, infection structure formation, and early colony development of powdery mildew on poinsettia.

    PubMed

    Celio, G J; Hausbeck, M K

    1998-02-01

    ABSTRACT Powdery mildew disease on poinsettias (Euphorbia pulcherrima) growing in commercial greenhouses was first observed in the United States in 1990 and has become an economically significant problem for poinsettia growers in the Midwest and northern United States since 1992. The temporal development of infection structures produced by conidial germ tubes of the pathogen (Oidium sp.) and the effect of high temperature on their development were investigated using poinsettia leaf disks placed in humidity chambers. Observations were made using light microscopy and scanning electron microscopy. At 20 degrees C (85% relative humidity), conidia germinated and formed an appressorium within 6 h of inoculation. Germination over time followed a monomolecular curve (r(2) = 0.77, P conidia had formed secondary germ tubes and a haustorium. The percentage of germinated conidia with appressoria and one or more secondary germ tubes increased linearly with time (r(2) = 0.92, P conidia with appressoria and haustoria increased mono-molecularly (r(2) = 0.93, P Conidia had an ornamented appearance, and all conidiophores had arced basal cells. When the incubation temperature was 30 degrees C, conidial germination and development of secondary germ tubes and a haustorium were reduced. PMID:18944978

  3. Susceptibility of Brevipalpus phoenicis to entomopathogenic fungi.

    PubMed

    Rossi-Zalaf, Luciana Savoi; Alves, Sérgio Batista

    2006-01-01

    The pathogenicity of 52 isolates from several fungus species was studied for the false spider mite Brevipalpus phoenicis. In addition, the main stages during the course of infection by Hirsutella thompsonii, by far the most virulent pathogen, were studied by means of light and electron microscopy. Adult mites were confined to arenas prepared with citrus leaves in acrylic dishes containing agar-water. Conidial suspensions containing 10(8) conidia/ml were applied, except for H. thompsonii, where a concentration of 10(7) conidia/ml was used. The H. thompsonii isolates caused higher mortality, with indices higher than 90%. Observations under the scanning electron microscope (SEM) were performed at 0, 6, 12, 24, 48, 72, and 120 h after application of a H. thompsonii suspension containing 10(7) conidia/ml. Twenty-four hours after inoculation, H. thompsonii conidia were observed attached to the mite's integument. The conidia germinated and penetrated through the base of the setae on the hysterosoma. Colonization occurred after 48 h, as evidenced by mortality. Conidiogenesis occurred after 120 h, with the development of mycelium and conidiophores emerging from the posterior and anterior parts of the mite. PMID:17004029

  4. Lipase production and Penicillium simplicissimum morphology in solid-state and submerged fermentations.

    PubMed

    Gutarra, Melissa Limoeiro Estrada; de Godoy, Mateus Gomes; Silva, Jaqueline do Nascimento; Guedes, Iamê Alves; Lins, Ulysses; Castilho, Leda Dos Reis; Freire, Denise Maria Guimarães

    2009-10-01

    A comparative study of Penicillium simplicissimum morphology and lipase production was performed using solid-state (SSF) and submerged (SmF) fermentation. SSF was carried out on babassu cake as culture medium and SmF on a semi-synthetic medium and a medium based on suspended babassu cake grains. Yield of product on biomass, specific activity and conidia production were 3.3-, 1.3- and 2-fold higher in SSF. In SmF, the type of fungus growth differed according to the medium. Using the semi-synthetic medium, the fungus formed densely interwoven mycelial masses without conidia production, whereas using the babassu-based medium the fungus formed free mycelia and adhered to the surfaces of the grains, producing conidia. The results show that babassu cake induces conidiation in SmF. In SSF, the fungus not only grew on the surface of the grains, producing conidia abundantly, but also effectively colonized and penetrated the babassu particles. The high conidia production and lipase productivity in SSF may be related to the low availability of nutrients or to other stimuli associated with this type of fermentation. Thus, the high production of the thermostable P. simplicissimum lipase, using a non-supplemented, low-cost agro-industrial residue as the culture medium, demonstrates the biotechnological potential of SSF for the production of industrial enzymes. PMID:19606429

  5. Monitoring environmental Aspergillus spp. contamination and meteorological factors in a haematological unit.

    PubMed

    Cavallo, M; Andreoni, S; Martinotti, M G; Rinaldi, M; Fracchia, L

    2013-12-01

    The opportunistic pathogens belonging to the Aspergillus genus are present in almost all seasons of the year, and their concentration is related to meteorological conditions. The high density of Aspergillus spp. conidia in a haematological hospital ward may be a significant risk factor for developing invasive fungal diseases in immunocompromised patients. Aim of the present study was to evaluate the variability of airborne Aspergillus spp. conidia contamination in a Haematological Unit (HU) within a period of 16 months in relation with some meteorological parameters. An environmental Aspergillus surveillance was conducted in the HU in four rooms and their bathrooms, in the corridor and in three external sites using an agar impact sampler. During each sampling, temperature and relative humidity at each site were recorded and current wind speed and rainfall events were taken from the official weather service. Aspergillus spp. conidia concentration differed significantly across the sampling sites. Internal Aspergillus spp. loads were significantly dependent on temperature, internal relative humidity and rain. External conidia concentrations were significantly influenced by outdoor temperature and relative humidity. A suitable indicator was introduced to evaluate the seasonal distribution of Aspergillus spp. conidia in the sampling sites, and a significant dependence on this indicator was observed inside the HU. Seventeen different fungal species belonging to the Aspergillus genus were detected during the sampling period. Aspergillus fumigatus was the most frequently isolated species and its distribution depended significantly on the seasonal indicator both inside and outside the hospital ward. PMID:24158616

  6. Resting spore formation of aphid-pathogenic fungus Pandora nouryi depends on the concentration of infective inoculum.

    PubMed

    Huang, Zhi-Hong; Feng, Ming-Guang

    2008-07-01

    Resting spore formation of some aphid-pathogenic Entomophthorales is important for the seasonal pattern of their prevalence and survival but this process is poorly understood. To explore the possible mechanism involved in the process, Pandora nouryi (obligate aphid pathogen) interacted with green peach aphid Myzus persicae on cabbage leaves under favourable conditions. Host nymphs showered with primary conidia of an isolate (LC(50): 0.9-6.7 conidia mm(-2) 4-7 days post shower) from air captures in the low-latitude plateau of China produced resting spores (azygospores), primary conidia or both spore types. Surprisingly, the proportion of mycosed cadavers forming resting spores (P(CFRS)) increased sharply within the concentrations (C) of 28-240 conidia mm(-2), retained high levels at 240-1760, but was zero or extremely low at 0.3-16. The P(CFRS)-C relationship fit well the logistic equation P(CFRS) = 0.6774/[1 + exp(3.1229-0.0270C)] (r(2) = 0.975). This clarified for the first time the dependence of in vivo resting spore formation of P. nouryi upon the concentration of infective inoculum. A hypothesis is thus proposed that some sort of biochemical signals may exist in the host-pathogen interaction so that the fungal pathogen perceives the signals for prompt response to forthcoming host-density changes by either producing conidia for infecting available hosts or forming resting spores for surviving host absence in situ. PMID:18341580

  7. Virulence of Entomopathogenic Fungi Metarhizium anisopliae and Paecilomyces fumosoroseus for the Microbial Control of Spodoptera exigua

    PubMed Central

    Han, Ji Hee; Jin, Byung Rae; Lee, Sang Yeob

    2014-01-01

    The beet armyworm Spodoptera exigua (Lepidoptera: Noctuidae) is difficult to control using chemical insecticides because of the development of insecticide resistance. Several pest control agents are used to control the beet armyworm. Entomopathogenic fungi are one of the candidates for eco-friendly pest control instead of chemical control agents. In this study, among various entomopathogenic fungal strains isolated from soil two isolates were selected as high virulence pathogens against larva of beet armyworm. Control efficacy of fungal conidia was influenced by conidia concentration, temperature, and relative humidity (RH). The isolates Metarhizium anisopliae FT83 showed 100% cumulative mortality against second instar larvae of S. exigua 3 days after treatment at 1 × 107 conidia/mL and Paecilomyces fumosoroseus FG340 caused 100% mortality 6 days after treatment at 1 × 104 conidia/mL. Both M. anisopliae FT83 and P. fumosoroseus FG340 effectively controlled the moth at 20~30℃. M. anisopliae FT83 was significantly affected mortality by RH: mortality was 86.7% at 85% RH and 13.4% at 45% RH. P. fumosoroseus FG340 showed high mortality as 90% at 45% RH and 100% at 75% RH 6 days after conidia treatments. These results suggest that P. fumosoroseus FG340 and M. anisopliae FT83 have high potential to develop as a biocontrol agent against the beet armyworm. PMID:25606011

  8. Ethanol and phenanthrene increase the biomass of fungal assemblages and decrease plant litter decomposition in streams.

    PubMed

    Barros, Diana; Oliveira, Patrícia; Pascoal, Cláudia; Cássio, Fernanda

    2016-09-15

    Fungi, particularly aquatic hyphomycetes, have been recognized as playing a dominant role in microbial decomposition of plant litter in streams. In this study, we used a microcosm experiment with different levels of fungal diversity (species number and identity) using monocultures and combinations with up to five aquatic hyphomycete species (Articulospora tetracladia, Tricladium splendens, Heliscus submersus, Tetrachaetum elegans and Flagellospora curta) to assess the effects of ethanol and phenanthrene on three functional measures: plant litter decomposition, fungal biomass accrual and reproduction. Alder leaves were conditioned by fungi for 7days and then were exposed to phenanthrene (1mgL(-1)) dissolved in ethanol (0.1% final concentration) or ethanol (at the concentration used to solubilise phenanthrene) for further 24days. Exposure to ethanol alone or in combination with phenanthrene decreased leaf decomposition and fungal reproduction, but increased fungal biomass produced. All aspects of fungal activity varied with species number. Fungal activity in polycultures was generally higher than that expected from the sum of the weighted performances of participating species in monoculture, suggesting complementarity between species. However, the activity of fungi in polycultures did not exceed the activity of the most productive species either in the absence or presence of ethanol alone or with phenanthrene. PMID:27186876

  9. Fungi and bacteria involved in desert varnish formation.

    PubMed

    Taylor-George, S; Palmer, F; Staley, J T; Borns, D J; Curtiss, B; Adams, J B

    1983-10-01

    Desert varnish is a coating of ferromanganese oxides and clays that develops on rock surfaces in arid to semi-arid regions. Active respiration but not photosynthesis was detected on varnished rock surfaces from the Sonoran Desert. Light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations, and cultivation experiments indicate that both fungi, primarily dematiaceous hyphomycetes, and bacteria are found on and within desert varnish coatings from the arid regions studied. Some fungi grow as microcolonial fungi (MCF) on rocks, and microscopic observations suggest MCF become incorporated in the varnish coating. SEM-EDAX (energy dispersive X-ray systems) analyses indicate the MCF contain 3 of the characteristic elements of varnish: iron, aluminum, and silicon. In some locations, MCF are also enriched in manganese relative to the rock substratum. Furthermore, some of the dematiaceous hyphomycetes that have been cultivated are able to oxidize manganese under laboratory conditions. It is possible that manganese-oxidizing bacteria, which are found in varnish, also play an important role in varnish formation. PMID:24221703

  10. Fungi and bacteria involved in desert varnish formation

    NASA Technical Reports Server (NTRS)

    Taylor-George, S.; Palmer, F.; Staley, J. T.; Curtiss, B.; Adams, J. B.; Borns, D. J.

    1983-01-01

    Desert varnish is a coating of ferromanganese oxides and clays that develops on rock surfaces in arid to semi-arid regions. Active respiration but not photosynthesis was detected on varnished rock surfaces from the Sonoran Desert. Light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations, and cultivation experiments indicate that both fungi, primarily dematiaceous hyphomycetes, and bacteria are found on and within desert varnish coatings from the arid regions studied. Some fungi grow as microcolonial fungi (MCF) on rocks, and microscopic observations suggest MCF become incorporated in the varnish coating. SEM-EDAX (energy dispersive X-ray systems) analyses indicate the MCF contain 3 of the characteristic elements of varnish: iron, aluminum, and silicon. In some locations, MCF are also enriched in manganese relative to the rock substratum. Furthermore, some of the dematiaceous hyphomycetes that have been cultivated are able to oxidize manganese under laboratory conditions. It is possible that manganese-oxidizing bacteria, which are found in varnish, also play an important role in varnish formation.