Isolation, characterization and industrial application of a Cladosporium herbarum fungal strain able to degrade the fungicide imazalil.

Imazalil (IMZ) is an imidazole fungicide commonly used by fruit-packaging plants (FPPs) to control fungal infections during storage. Its application leads to the production of pesticide-contaminated wastewaters, which, according to the European Commission, need to be treated on site. Considering the lack of efficient treatment methods, biodepuration systems inoculated with tailored-made inocula specialized on the removal of such persistent fungicides appear as an appropriate solution. However, nothing is known about the biodegradation of IMZ. We aimed to isolate and characterize microorganisms able to degrade the recalcitrant fungicide IMZ and eventually to test their removal efficiency under near practical bioengineering conditions. Enrichment cultures from a soil receiving regular discharges of effluents from a FPP, led to the isolation of a Cladosporium herbarum strain, which showed no pathogenicity on fruits, a trait essential for its biotechnological exploitation in FPPs. The fungus was able to degrade up to 100 mg L-1 of IMZ. However, its degrading capacity and growth was reduced at increasing IMZ concentrations in a dose-dependent manner, suggesting the involvement of a detoxification rather than an energy-gain mechanism in the dissipation of IMZ. The isolate could tolerate and gradually degrade the fungicides fludioxonil (FLD) and thiabendazole (TBZ), also used in FPPs and expected to coincide alongside IMZ in FPP effluents. The capacity of the isolate to remove IMZ in a practical context was evaluated in a benchtop immobilized-cell bioreactor fed with artificial IMZ-contaminated wastewater (200 mg L-1). The fungal strain established in the reactor, completely dominated the fungal community and effectively removed >96% of IMZ. The bioreactor also supported a diverse bacterial community composed of Sphingomonadales, Burkholderiales and Pseudomonadales. Our study reports the isolation of the first IMZ-degrading microorganism with high efficiency to remove IMZ from agro-industrial effluents under bioengineering conditions.

Resistance to diseases of sour, sweet and wild passion fruit genotypes

The cultivation of passion fruit is important for Brazil, since the country is currently the largest producer and consumer of fruit in the world. However, the fields of passion fruit still face important problems due to the incidence and severity of diseases in the field. Thus, the present study aimed to assess resistance to bacterial and fungal diseases in 13 genotypes of sour, sweet and wild passion fruit, in field conditions in the Distrito Federal, Brazil. For this, a field experiment was installed in a randomized block design, with four replications and 13 treatments (genotypes). The characteristics of incidence, severity and degree of resistance for bacteriosis, septoriosis, scab and anthracnose diseases were evaluated in 5 fruits per plot of each genotype. Genetic parameters of the evaluated traits were also estimated. High heritability values and CVg/Cve ratio were observed for most of the evaluated characteristics. The genotypes presented mean values of incidence and severity of bacteriosis, septoriosis, scab and anthracnose different among them, and the one that presented the best results in the degree of resistance for all diseases was F1 (MAR20 # 24 x ECL7 P1 R4).

Cladosporium herbarum Hot-Tub Lung Hypersensitivity Pneumonitis in a Greenhouse Worker.

Hypersensitivity pneumonitis is understood to be a delayed allergic reaction to the repeated exposure of a usually innocent inhaled agent, causing inflammatory damage to the pulmonary parenchyma, alveoli and terminal bronchioles. With ongoing exposure, it can cause respiratory compromise and pulmonary fibrosis. Recognizing the heterogeneity of the causative agents and the low incidence of the disease, we considered it important to report the case of a greenhouse worker who developed a Cladosporium sp. related hot-tub lung hypersensitivity pneumonitis. We believe it to be the first reported case of a greenhouse occupational hypersensitivity pneumonitis due to Cladosporium sp. LEARNING POINTS: Enquiring about environmental and occupational exposure during anamnesis is fundamental, particularly when addressing respiratory tract symptoms.The mainstay management of hypersensitivity pneumonitis is based on eviction of the offending agent and control of inflammation, currently with corticosteroids.Antigen source removal may entail important psychological, social and economic consequences for the patient and will need a multidisciplinary approach.

Dynamic Surface Proteomes of Allergenic Fungal Conidia.

Fungal spores and hyphal fragments play an important role as allergens in respiratory diseases. In this study, we performed trypsin shaving and secretome analyses to identify the surface-exposed proteins and secreted/shed proteins of Aspergillus fumigatus conidia, respectively. We investigated the surface proteome under different conditions, including temperature variation and germination. We found that the surface proteome of resting A. fumigatus conidia is not static but instead unexpectedly dynamic, as evidenced by drastically different surface proteomes under different growth conditions. Knockouts of two abundant A. fumigatus surface proteins, ScwA and CweA, were found to function only in fine-tuning the cell wall stress response, implying that the conidial surface is very robust against perturbations. We then compared the surface proteome of A. fumigatus to other allergy-inducing molds, including Alternaria alternata, Penicillium rubens, and Cladosporium herbarum, and performed comparative proteomics on resting and swollen conidia, as well as secreted proteins from germinating conidia. We detected 125 protein ortholog groups, including 80 with putative catalytic activity, in the extracellular region of all four molds, and 42 nonorthologous proteins produced solely by A. fumigatus. Ultimately, this study highlights the dynamic nature of the A. fumigatus conidial surface and provides targets for future diagnostics and immunotherapy.

A peptidogalactomannan isolated from Cladosporium herbarum induces defense-related genes in BY-2 tobacco cells.

Cladosporium herbarum is a plant pathogen associated with passion fruit scab and mild diseases in pea and soybean. In this study, a peptidogalactomannan (pGM) of C. herbarum mycelium was isolated and structurally characterized, and its role in plant-fungus interactions was evaluated. C. herbarum pGM is composed of carbohydrates (76%) and contains mannose, galactose and glucose as its main monosaccharides (molar ratio, 52:36:12). Methylation and 13C-nuclear magnetic resonance (13C-NMR) spectroscopy analysis have shown the presence of a main chain containing (1 → 6)-linked α-D-Manp residues, and ß-D-Galf residues are present as (1 → 5)-interlinked side chains. ß-Galactofuranose containing similar structures were characterized by our group in A. fumigatus, A. versicolor, A. flavus and C. resinae. Tobacco BY-2 cells were used as a model system to address the question of the role of C. herbarum pGM in cell viability and induction of the expression of plant defense-related genes. Native and partially acid hydrolyzed pGMs (lacking galactofuranosyl side-chain residues) were incubated with BY-2 cell suspensions at different concentrations. Cell viability drastically decreased after exposure to more than 400 µg ml-1 pGM; however no cell viability effect was observed after exposure to a partially acid hydrolyzed pGM. BY-2 cell contact with pGM strongly induce the expression of plant defense-related genes, such as phenylalanine ammonia lyase (PAL) and lipoxygenase (LOX), as well as the pathogen-related PR-1a, PR-2 and PR-3 genes, suggesting that pGM activates defense responses in tobacco cells. Interestingly, contact with partially hydrolyzed pGM also induced defense-related gene expression at earlier times than native pGM. These results show that the side chains of the (1 → 5)-linked ß-D-galactofuranosyl units from pGM play an important role in the first line fungus-plant interactions mediating plant responses against C. herbarum. In addition, it was observed that pGM and/or C. herbarum conidia are able to induced HR when in contact with tobacco leaves and in vitro plantlets roots, producing necrotic lesions and peroxidase and NO burst, respectively.

Iridoid glucoside and antifungal phenolic compounds from Spathodea campanulata roots / Iridóide glicosilado e derivados fenólicos antifúngicos isoladosdas raízes de Spathodea campanulata

The chemical study of Spathodea campanulata (Bignoniaceae) roots peels afforded an iridoid glucoside(ajugol) and two phenolic derivatives (p-hydroxy-benzoic acid and methyl p-hydroxy-benzoate). Thecompounds were characterized upon spectral data interpretation. Bioactivities of the constituents wereevaluated against fungus Cladosporium herbarum.

O estudo químico das cascas das raízes de Spathodea campanulata (Bignoniaceae) conduziu ao isolamentode um irióide glicosilado (ajugol) e dois derivados fenólicos (ácido p-hidroxi-benzóico e p-hidroxi-benzoato demetila). Os compostos foram identificados com base na interpretação dos seus dados espectrais. A atividadebiológica destes constituintes foi avaliada contra o fungo Cladosporium herbarum

Occurrence of Strawberry Scab Caused by Cladosporium herbarum in Korea

A black scab was observed on strawberry(Fragaria ananassa) in plastic film houses around Jinju area during the winter of 2000. The disease started from leaves then moved to calyx and runner. At the beginning, the infected area started with small dark brown spots then gradually expanded. The pathogenic fungus was purely isolated from the diseased leaves, calyx and runner. The fungus was inoculated to test Koch's postulates and proved to be the causal agent of the disease. The isolated fungus grew readily on potato dextrose agar, forming dark green to dark gray colonies. The optimum temperature for mycelial growth was about 25degrees C. The diameter of growing hyphae was 3.8~5.6 microm. Conidia were ellipsoidal, ovoid or subspherical, mostly one-celled but occasionally septate. The size of conidia were 4.1~11.7x3.8~5.3 1-cell, 9.3~18.8x4.0~7.4 microm 2-cell and formed in long branched chains on the erected conidiophores which were dark brown and variable in length between 28.8~236.2x3.0~6.2 microm in size. The fungus was identified as Cladosporium herbarum on the basis of its morphological characteristics. The black scab disease of strawberry caused by C. herbarum has not been reported in Korea previously.