The biosorption of chromium (VI) on eighteen different natural biosorbents: Natural sediment, chitosan,
chitin, Aspergillus flavus I-V, Aspergillus fumigatus I-ll, Helmintosporium sp, Cladosporium sp, Mucor rouxii mutant, M. rouxii IM-80, Mucor sp-I and 2, Candida albicans and Cryptococcus neoformans was studied in this work. It was found that the biomass of C. neoformans, natural sediment, Helmintosporium sp and chitosan was more efficient to remove chromium (VI) (determined spectrophotometrically at 540 nm
using diphenylcarbazide as the complexing agent) achieving the. following percentage of removals: 98%,
98% and 63%, respectively. The highest adsorption was obtained with C. neoformans and Helmintosporium
sp at pH 2.0 and 4.0 + 0.2, respectively, at 28∘C after 24 hours of incubation, with 0.2 mg/L of cellular
Many pathogenic fungi are dimorphic and switch between yeast and filamentous states. This switch alters host-microbe interactions and is critical for pathogenicity. However, in zygomycetes, whether dimorphism contributes to virulence is a central unanswered question. The pathogenic zygomycete Mucor circinelloides exhibits hyphal growth in aerobic conditions but switches to multi-budded yeast growth under anaerobic/high CO2 conditions. We found that in the presence of the calcineurin inhibitor FK506, Mucor exhibits exclusively multi-budded yeast growth. We also found that M. circinelloides encodes three calcineurin catalytic A subunits (CnaA, CnaB, and CnaC) and one calcineurin regulatory B subunit (CnbR). Mutations in the latch region of CnbR and in the FKBP12-FK506 binding domain of CnaA result in hyphal growth of Mucor in the presence of FK506. Disruption of the cnbR gene encoding the sole calcineurin B subunit necessary for calcineurin activity yielded mutants locked in permanent yeast phase growth. These findings reveal that the calcineurin pathway plays key roles in the dimorphic transition from yeast to hyphae. The cnbR yeast-locked mutants are less virulent than the wild-type strain in a heterologous host system, providing evidence that hyphae or the yeast-hyphal transition are linked to virulence. Protein kinase A activity (PKA) is elevated during yeast growth under anaerobic conditions, in the presence of FK506, or in the yeast-locked cnbR mutants, suggesting a novel connection between PKA and calcineurin. cnaA mutants lacking the CnaA catalytic subunit are hypersensitive to calcineurin inhibitors, display a hyphal polarity defect, and produce a mixture of yeast and hyphae in aerobic culture. The cnaA mutants also produce spores that are larger than wild-type, and spore size is correlated with virulence potential. Our results demonstrate that the calcineurin pathway orchestrates the yeast-hyphal and spore size dimorphic transitions that contribute to virulence of this common zygomycete fungal pathogen.
Calcineurin is a Ca2+/calmodulin-dependent, serine/threonine-specific protein phosphatase. In pathogenic fungi, calcineurin is involved in morphogenesis and virulence. Therefore, calcineurin is an attractive antifungal drug target. The roles of calcineurin in virulence have been established in both major human pathogenic fungi (Candida species, Cryptococcus neoformans/gattii, Aspergillus fumigatus) and in plant pathogenic fungi (Magnaporthe oryzae, Ustilago maydis/hordei). However, the role of calcineurin is currently unknown in pathogenic zygomycetes. We found that the calcineurin inhibitors FK506 and cyclosporine A inhibit the growth of a prevalent zygomycete pathogen, Mucor. This fungus grows as multi-budded yeast under anaerobic conditions, and we have found that even in aerated culture (which without FK506 would result in abundant hyphal growth), Mucor exhibits yeast growth when exposed to FK506. Mucor cnbR mutants that lack the calcineurin regulatory subunit essential for calcineurin activity, are locked in perpetual yeast phase growth, indicating that calcineurin is required for hyphal growth. We further demonstrated that these yeast-locked mutants are attenuated for virulence, illustrating that hyphae or the yeast-hyphal transition are linked to virulence. These findings indicate that: 1) calcineurin governs the yeast/hyphae morphogenic transition; 2) a link exists between respiration and the calcineurin pathway; and 3) calcineurin inhibitors are attractive anti-mucormycosis drug candidates.
Rapid detection and differentiation of Aspergillus and Mucorales species in fungal rhinosinusitis diagnosis are desirable, since the clinical management and prognosis associated with the two taxa are fundamentally different. We describe an assay based on a combination of broad-range PCR amplification and reverse line blot hybridization (PCR/RLB) to detect and differentiate the pathogens causing fungal rhinosinusitis, which include five Aspergillus species (A. fumigatus, A. flavus, A. niger, A. terreus, and A. nidulans) and seven Mucorales species (Mucor heimalis, Mucor racemosus, Mucor cercinelloidea, Rhizopus arrhizus, Rhizopus microsporus, Rhizomucor pusillus, and Absidia corymbifera). The assay was validated with 98 well-characterized clinical isolates and 41 clinical tissue specimens. PCR/RLB showed high sensitivity and specificity, with 100% correct identifications of 98 clinical isolates and no cross-hybridization between the species-specific probes. Results for five control isolates, Candida albicans, Fusarium solani, Scedosporium apiospermum, Penicillium marneffei, and Exophiala verrucosa, were negative as judged by PCR/RLB. The analytical sensitivity of PCR/RLB was found to be 1.8 × 10−3 ng/μl by 10-fold serial dilution of Aspergillus genomic DNA. The assay identified 35 of 41 (85.4%) clinical specimens, exhibiting a higher sensitivity than fungal culture (22 of 41; 53.7%) and direct sequencing (18 of 41; 43.9%). PCR/RLB similarly showed high specificity, with correct identification 16 of 18 specimens detected by internal transcribed spacer (ITS) sequencing and 16 of 22 detected by fungal culture, but it also has the additional advantage of being able to detect mixed infection in a single clinical specimen. The PCR/RLB assay thus provides a rapid and reliable option for laboratory diagnosis of fungal rhinosinusitis.
Invasive fungal infections (IFI) remain a serious threat to immunocompromised hosts. Current diagnostic methods, including fungal culture and antigen detection, are slow and often lack specificity. Rapid diagnostic tools with increased sensitivity and specificity could improve the care of patients with IFI. Recently, Luminex Molecular Diagnostics (Toronto, Canada) developed 23 analyte-specific reagents (ASRs) for the detection of the most common clinically relevant fungi. This study's objective was to evaluate the sensitivity and specificity of a subset of these ASRs for fungal isolates and clinical specimens. Previously characterized fungal and bacterial isolates (n = 110), blood culture specimens (n = 34), and respiratory specimens (n = 44) were tested using either a Candida 7-plex panel (Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, Candida lusitaniae, Candida guilliermondii, and Candida krusei) or a mold 11-plex panel (Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Aspergillus terreus, Scedosporium prolificans, Scedosporium apiospermum, Fusarium oxysporum/Fusarium solani, Rhizopus arrhizus, Rhizopus microsporus, Mucor indicus, and Cunninghamella bertholletiae). The Candida 7-plex panel correctly identified all Candida isolates as confirmed by fungal culture and biochemical tests, for a sensitivity and specificity of 100%. The mold 11-plex panel correctly identified all mold isolates tested except for A. niger. Fungal isolates of Rhizopus and Mucor species were not detected, either, although they could represent species other than those targeted by the ASRs. Further evaluation will be necessary to confirm the sensitivities of some of the mold ASRs. Implementation of these ASRs will allow same-day detection of fungal DNA in clinical specimens.
The performances of nine biosorbents derived from dead fungal biomass were investigated for their ability to remove Reactive Black 5 from aqueous solution. The biosorption data for removal of Reactive Black 5 were readily modeled using the Langmuir adsorption isotherm. Kinetic analysis based on both pseudo-second-order and Weber-Morris models indicated intraparticle diffusion was the rate limiting step for biosorption of Reactive Black 5 on to the biosorbents. Sorption capacities of the biosorbents were not correlated with the initial biosorption rates. Sensitivity analysis of the factors affecting biosorption examined by an artificial neural network model showed that pH was the most important parameter, explaining 22%, followed by nitrogen content of biosorbents (16%), initial dye concentration (15%) and carbon content of biosorbents (10%). The biosorption capacities were not proportional to surface areas of the sorbents, but were instead influenced by their chemical element composition. The main functional groups contributing to dye sorption were amine, carboxylic, and alcohol moieties. The data further suggest that differences in carbon and nitrogen contents of biosorbents may be used as a selection index for identifying effective biosorbents from dead fungal biomass.
Biosorption of Cd(II) ions from aqueous solutions by native and dried Oscillatoria sp. Cyanobacterium biomass was investigated in the batch mode. The Oscillatoria sp. was prepared from Molecular and Cell Laboratory of University of Mazandaran and grown in BG-11 medium. A comparison of Cd(II) adsorption properties of dried with native Oscillatoria sp. biomass was made, the dried one showed a higher biosorption capacity and faster kinetic. The influence of solution pH, contact time, biomass concentration, initial metal ion concentration, and presence of coions using dried Oscillatoria sp. biomass as well as pretreatment on the biosorption capacity of the biomass were studied. Various pretreatments of Oscillatoria sp. increased biosorption of Cd(II) at pH 7 in comparison with native biomass. However, heating at 100°C in a water bath showed significant improvement in Cd(II) biosorption capacity. The experimental biosorption data was well fitted to the Freundlich model compared to the Langmuir model, and the amount of Cd(II) removed from solution increased with increasing Cd(II) concentration. In addition, the dried biomass was investigated for Cd(II) removal from the simulated real sample containing about 14 mg/l Cd(II) at pH 7, under the same experimental condition.
The present work represents the biosorption of Cd(II) and Pb(II) from aqueous solution onto the biomass of the blue green alga Anabaena sphaerica as a function of pH, biosorbent dosage, contact time, and initial metal ion concentrations. Freundlich, Langmuir, and Dubinin–Radushkevich (D–R) models were applied to describe the biosorption isotherm of both metals by A. sphaerica biomass. The biosorption isotherms studies indicated that the biosorption of Cd(II) and Pb(II) follows the Langmuir and Freundlish models. The maximum biosorption capacities (qmax) were 111.1 and 121.95 mg/g, respectively, at the optimum conditions for each metal. From the D–R isotherm model, the mean free energy was calculated to be 11.7 and 14.3 kJ/mol indicating that the biosorption mechanism of Cd(II) and Pb(II) by A. sphaerica was chemisorption. The FTIR analysis for surface function group of algal biomass revealed the existence of amino, carboxyl, hydroxyl, and carbonyl groups, which are responsible for the biosorption of Cd(II) and Pb(II). The results suggested that the biomass of A. sphaerica is an extremely efficient biosorbent for the removal of Cd(II) and Pb(II) from aqueous solutions.
Anabaena sphaerica; Alga; Biosorption; Heavy metals
We developed a PCR-based assay to differentiate medically important species of Aspergillus from one another and from other opportunistic molds and yeasts by employing universal, fungus-specific primers and DNA probes in an enzyme immunoassay format (PCR-EIA). Oligonucleotide probes, directed to the internal transcribed spacer 2 region of ribosomal DNA from Aspergillus flavus, Aspergillus fumigatus, Aspergillus nidulans, Aspergillus niger, Aspergillus terreus, Aspergillus ustus, and Aspergillus versicolor, differentiated 41 isolates (3 to 9 each of the respective species; P < 0.001) in a PCR-EIA detection matrix and gave no false-positive reactions with 33 species of Acremonium, Exophiala, Candida, Fusarium, Mucor, Paecilomyces, Penicillium, Rhizopus, Scedosporium, Sporothrix, or other aspergilli tested. A single DNA probe to detect all seven of the most medically important Aspergillus species (A. flavus, A. fumigatus, A. nidulans, A. niger, A. terreus, A. ustus, and A. versicolor) was also designed. Identification of Aspergillus species was accomplished within a single day by the PCR-EIA, and as little as 0.5 pg of fungal DNA could be detected by this system. In addition, fungal DNA extracted from tissues of experimentally infected rabbits was successfully amplified and identified using the PCR-EIA system. This method is simple, rapid, and sensitive for the identification of medically important Aspergillus species and for their differentiation from other opportunistic fungi.
The increasing incidence of invasive fungal infections (IFI) in immunocompromised patients emphasizes the need to improve diagnostic tools. We established a DNA microarray to detect and identify DNA from 14 fungal pathogens (Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus, Candida albicans, Candida dubliniensis, Candida glabrata, Candida lusitaniae, Candida tropicalis, Fusarium oxysporum, Fusarium solani, Mucor racemosus, Rhizopus microsporus, Scedosporium prolificans, and Trichosporon asahii) in blood, bronchoalveolar lavage, and tissue samples from high-risk patients. The assay combines multiplex PCR and consecutive DNA microarray hybridization. PCR primers and capture probes were derived from unique sequences of the 18S, 5.8S, and internal transcribed spacer 1 regions of the fungal rRNA genes. Hybridization with genomic DNA of fungal species resulted in species-specific hybridization patterns. By testing clinical samples from 46 neutropenic patients with proven, probable, or possible IFI or without IFI, we detected A. flavus, A. fumigatus, C. albicans, C. dubliniensis, C. glabrata, F. oxysporum, F. solani, R. microsporus, S. prolificans, and T. asahii. For 22 of 22 patients (5 without IFI and 17 with possible IFI), negative diagnostic results corresponded with negative microarray data. For 11 patients with proven (n = 4), probable (n = 2), and possible IFI (n = 5), data for results positive by microarray were validated by other diagnostic findings. For 11 of 11 patients with possible IFI, the microarray results provided additional information. For two patients with proven and probable invasive aspergillosis, respectively, microarray results were negative. The assay detected genomic DNA from 14 fungal pathogens from the clinical samples, pointing to a high significance for improving the diagnosis of IFI.
Bartnicki-Garcia, S. (Rutgers, The State University, New Brunswick, N.J.) and Walter J. Nickerson. Nutrition, growth, and morphogenesis of Mucor rouxii. J. Bacteriol. 84:841–858. 1962.—Mucor rouxii was grown under three different atmospheres of incubation: air, N2, and CO2 in parallel cultures. The atmosphere of incubation markedly affected nutritional requirements, growth, and morphogenesis. Absence of oxygen greatly reduced growth and increased the nutritional demands of the fungus. Presence of a high tension of CO2 resulted in a change from filamentous to yeastlike morphogenesis. Aerobically, a large variety of carbon sources was utilized; anaerobically, only hexoses served to meet requirements for carbon and energy. Aerobically, various amino acids supported abundant growth; anaerobically, they were poorly utilized. Ammonium and nitrate ions were better sources of nitrogen for anaerobic growth. In general, incubation under either air or N2 resulted in development of coenocytic filamentous mycelium, whereas incubation under CO2 resulted in development of budding yeastlike cells. Variations in temperature and time of incubation, inoculum size, type and concentration of carbon source, type of nitrogen source, and presence of various substances with known action on fungal morphogenesis altered growth in many cases, but did not significantly affect the patterns of vegetative morphogenesis conditioned by each atmosphere of incubation. However, vegetative morphogenesis was strongly affected by addition of certain chelating agents. Yeastlike development of M. rouxii was prevented by ethylene-diaminetetraacetic acid (EDTA) in concentrations which were also partially inhibitory for growth; under these conditions, development was filamentous. Chemically related chelating agents were similarly active. The growth-inhibitory and morphogenetic effects of EDTA were reversed by transition-group metal ions. Yeastlike development of M. subtilissimus, which does not require CO2 for its induction, was also inhibited by EDTA.
The biosorption of hexavalent chromium from aqueous solutions by Opuntia cladodes and ectodermis from cactus fruits was investigated. Both types of biomass are considered low-cost, natural, and ecofriendly biosorbents. Batch experiments were carried out to determine Cr(VI) biosorption capacity and the efficiency of the biosorption process under different pH, initial Cr(VI) concentration, and sorbent dosage. The biosorption of Cr(VI) by Opuntia biomass was highly pH dependent, favoring higher metal uptake at low pH. The higher biosorption capacity was exhibited at pH 2. The optimal conditions were obtained at a sorbent dosage of 1 g L−1 and initial metal concentration of 10 mg L−1. Biosorption kinetic data were properly fitted with the pseudo-second-order kinetic model. The rate constant, the initial biosorption rate, and the equilibrium biosorption capacity were determined. The experimental equilibrium data obtained were analyzed using two-parameter isotherm models (Langmuir, Freundlich, and Temkin). The Langmuir maximum monolayer biosorption capacity (qmax) was 18.5 mg g−1 for cladodes and 16.4 mg g−1 for ectodermis. The results suggest that Opuntia biomass could be considered a promising low-cost biosorbent for the ecofriendly removal of Cr(VI) from aqueous systems.
Dyes released into the environment have been posing a serious threat to natural ecosystems and aquatic life due to presence of heat, light, chemical and other exposures stable. In this study, the Pleurotus ostreatus (a macro-fungus) was used as a new biosorbent to study the biosorption of hazardous malachite green (MG) from aqueous solutions. The effective disposal of P. ostreatus is a meaningful work for environmental protection and maximum utilization of agricultural residues.
The operational parameters such as biosorbent dose, pH, and ionic strength were investigated in a series of batch studies at 25°C. Freundlich isotherm model was described well for the biosorption equilibrium data. The biosorption process followed the pseudo-second-order kinetic model. Taguchi method was used to simplify the experimental number for determining the significance of factors and the optimum levels of experimental factors for MG biosorption. Biosorbent dose and initial MG concentration had significant influences on the percent removal and biosorption capacity. The highest percent removal reached 89.58% and the largest biosorption capacity reached 32.33 mg/g. The Fourier transform infrared spectroscopy (FTIR) showed that the functional groups such as, carboxyl, hydroxyl, amino and phosphonate groups on the biosorbent surface could be the potential adsorption sites for MG biosorption. P. ostreatus can be considered as an alternative biosorbent for the removal of dyes from aqueous solutions.
Malachite green; Pleurotus ostreatus; Biosorption; Taguchi method
The use of dried and re-hydrated biomass of the seagrass Posidonia oceanica was investigated as an alternative and –low-cost biomaterial for removal of vanadium(III) and molybdenum(V) from wastewaters. Initial characterisation of this biomaterial identified carboxylic groups on the cuticle as potentially responsible for cation sorption, and confirmed the toxic-metal bioaccumulation. The combined effects on biosorption performance of equilibrium pH and metal concentrations were investigated in an ideal single-metal system and in more real-life multicomponent systems. There were either with one metal (vanadium or molybdenum) and sodium nitrate, as representative of high ionic strength systems, or with the two metals (vanadium and molybdenum). For the single-metal solutions, the optimum was at pH 3, where a significant proportion of vanadium was removed (ca. 70%) while there was ca. 40% adsorption of molybdenum. The data obtained from the more real-life multicomponent systems showed that biosorption of one metal was improved both by the presence of the other metal and by high ionic strength, suggesting a synergistic effect on biosorption rather than competition. There data ware used for the development of a simple multi-metal equilibrium model based on the non-competitive Langmuir approach, which was successfully fitted to experimental data and represents a useful support tool for the prediction of biosorption performance in such real-life systems. Overall, the results suggest that biomass of P. oceanica can be used as an efficient biosorbent for removal of vanadium(III) and molybdenum(V) from aqueous solutions. This process thus offers an eco-compatible solution for the reuse of the waste material of leaves that accumulate on the beach due to both human activities and to storms at sea.
Mucor rouxii CFR-G15, a locally isolated phycomycetous fungus, on cultivation at room temperature produced more than 30% (w/w) lipid in their dry cell weight, in which 14.2% accounted to be GLA content of the total fatty acids. It was observed that when incubation temperature lowered at 14°C, GLA content of the mycelium increased significantly (P<0.05) from 14.2% to 21.97%. In order to optimize the cultural conditions for high biomass and lipid production with high GLA content, the fungus was grown in association of two different temperatures and supply of additional glucose in culture medium. Maximum lipid and GLA were obtained 23.56 and 19.5% respectively, when the culture was grown at 28°C for four days and followed by addition of glucose (5%), and lowered the incubation temperature to 14°C for another four days. The presence of GLA in the oil obtained from M. rouxii CFR-G15 was confirmed by the gas chromatography-mass spectrometry. Gamma linolenic acid (GLA, n-6) is gaining importance in pharmaceutical and nutraceutical industries because of clinical evidence demonstrated that it has various beneficial effects in human health. In this paper temperature played a major role in enhancing the GLA content which has been described.
Biomass; Gamma linolenic acid; Microbial lipids; Mucor rouxii; Polyunsaturated fatty acids
A high-d-xylulose mixture (d-xylose-d-xylulose = 33:67) was prepared from the cold ethanol extract of preisomerized d-xylose solution (d-xylose-d-xylulose = 77:23). Fusarium oxysporum f. sp. lini and Aspergillus niger were demonstrated to preferentially utilize d-xylose in the mixture of d-xylose and d-xylulose. Chromatographically pure d-xylulose was thus obtained in 90% yield. A high-d-xylulose mixture was also incubated with Rhodotorula toruloides, Klebsiella pneumoniae, Candida utilis, or Mucor rouxii.d-Xylose and d-xylulose were simultaneously consumed. When borate was added to the mixture, a d-xylulose-borate complex was formed, and it could be used to protect d-xylulose from being utilized.
The germination of fungal spores into hyphae was inhibited by concentrations of phenethyl alcohol (PEA) from 0.05 to 0.3%. Spores of Mucor formed budding spherical cells instead of filaments. These cells were abundant in cultures of Mucor rouxii at 0.22% PEA, provided that the carbon source was a hexose at 2 to 5%. Morphology was filamentous with xylose, maltose, sucrose, or a mixture of amino acids. Removal of PEA resulted in the conversion of yeast-like cells into hyphae. PEA did not inhibit biosynthesis of cytochromes or oxygen uptake, but it stimulated CO2 and ethyl alcohol production. PEA had no effect on the rate of oxygen uptake, but it inhibited the oxidative-phosphorylation activity of mitochondria. These results suggested that growth inhibition by PEA could result from uncoupling of oxidative phosphorylation and that, in Mucor, yeast-like morphology and fermentation were linked.
Fungal growth in damp or water-damaged buildings worldwide is an increasing problem, which has adverse effects on both the occupants and the buildings. Air sampling alone in moldy buildings does not reveal the full diversity of fungal species growing on building materials. One aim of this study was to estimate the qualitative and quantitative diversity of fungi growing on damp or water-damaged building materials. Another was to determine if associations exist between the most commonly found fungal species and different types of materials. More than 5,300 surface samples were taken by means of V8 contact plates from materials with visible fungal growth. Fungal identifications and information on building material components were analyzed using multivariate statistic methods to determine associations between fungi and material components. The results confirmed that Penicillium chrysogenum and Aspergillus versicolor are the most common fungal species in water-damaged buildings. The results also showed Chaetomium spp., Acremonium spp., and Ulocladium spp. to be very common on damp building materials. Analyses show that associated mycobiotas exist on different building materials. Associations were found between (i) Acremonium spp., Penicillium chrysogenum, Stachybotrys spp., Ulocladium spp., and gypsum and wallpaper, (ii) Arthrinium phaeospermum, Aureobasidium pullulans, Cladosporium herbarum, Trichoderma spp., yeasts, and different types of wood and plywood, and (iii) Aspergillus fumigatus, Aspergillus melleus, Aspergillus niger, Aspergillus ochraceus, Chaetomium spp., Mucor racemosus, Mucor spinosus, and concrete and other floor-related materials. These results can be used to develop new and resistant building materials and relevant allergen extracts and to help focus research on relevant mycotoxins, microbial volatile organic compounds (MVOCs), and microparticles released into the indoor environment.
Candida and Aspergillus spp., as well as other filamentous molds, have increasingly been reported as the causes of severe invasive fungal infections. We evaluated the new echinocandin aminocandin (AMN) for its antifungal activities against a range of fungal pathogens by determination of the MICs for the organisms. The MICs of the comparator drugs amphotericin B, caspofungin, micafungin, and voriconazole were also determined. The MICs of AMN for 25 strains each of non-Candida albicans Candida spp. (including Candida parapsilosis, Candida krusei, Candida guilliermondii, and Candida tropicalis), Aspergillus fumigatus, Scedosporium spp., Fusarium spp., and zygomycetes (including Absidia, Mucor, and Rhizopus spp.) were determined by using the Clinical and Laboratory Standards Institute M27-A2 and M38-A methodologies for yeasts and filamentous molds, respectively. The MIC ranges of AMN for all yeasts were similar (0.03 to 4.0 μg/ml), while the MIC ranges of AMN for filamentous fungi were species specific. AMN demonstrated potent antifungal activity against A. fumigatus, limited activity against Scedosporium spp., and no activity against zygomycetes or Fusarium spp. Our data showed that AMN demonstrated potent antifungal activities against all of the yeasts and Aspergillus isolates tested, suggesting that AMN could be an important addition to our arsenal of antifungals for the treatment of invasive fungal disease.
It is estimated that about 10% of the population have IgE antibodies to common inhalant molds. Exposure to fungal allergens could be linked to the presence and persistence of asthma, rhinitis and atopic dermatitis. Mold sensitization is a risk factor for development and deterioration of upper airway allergy, especially chronic rhinosinusitis. We addressed the incidence of mold allergy measured as specific IgE to molds and skin prick tests in chronic sinusitis patients. We assessed prevalence of allergic reactions to mould among surgery treated chronic sinusitis patients.
A group of 28 chronic sinusitis patients after surgery were included into the study. Routine medical examination, skin prick tests with common inhaled allergens and extended mold panel (Alternaria alternate, Cladosporium herbarium, Aspergilus fumigatus, Candida albicans, Mucor mucedo, Botrytis cinerea, Rhisopus nigricans, Penicilliumi notatum, Fusarum moniliforme Pullularia pullulans (Allergopharma, Germany), tIgE, asIgE measurement were performed (Phadia, Sweden). All investigated patients were consulted by laryngologist and mycological examination was performed.
We found that sensitization to at least one allergen was present in 43.8(14/32) of sinusitis patients. The most prevalent was sensitization to house dust mite Dermatophagoides pt., found in 21.8 % (7/32) patients. Positive results of skin prick tests with Candida albicans we observed in 18.8% (6/32), with Alternaria alternate in 15,6% (5/32), Cladosporium herbarium in 6,3% (2/32), Aspergilus fumigatus in 3,13 % (1/32). None of investigated patients presented sensitization to other mold allergens. Microbiological methods demonstrated fungal infection only in 2 patients.
Almost half of chronic sinusitis patients presented sensitization to at least one allergen. Fungal allergy is relatively rare in chronic sinusitis patients.
Posaconazole, ravuconazole, and voriconazole are new triazole derivatives that possess potent, broad-spectrum antifungal activity. We evaluated the in vitro activity of these investigational triazoles compared with that of itraconazole and amphotericin B against 239 clinical isolates of filamentous fungi from the SENTRY Program, including Aspergillus spp. (198 isolates), Fusarium spp. (7 isolates), Penicillium spp. (19 isolates), Rhizopus spp. (4 isolates), Mucor spp. (2 isolates), and miscellaneous species (9 isolates). The isolates were obtained from 16 different medical centers in the United States and Canada between January and December 2000. In vitro susceptibility testing was performed using the microdilution broth method outlined in the National Committee for Clinical Laboratory Standards M38-P document. Overall, posaconazole was the most active compound, inhibiting 94% of isolates at a MIC of ≤1 μg/ml, followed by voriconazole (91%), amphotericin B (89%), ravuconazole (88%), and itraconazole (70%). All three new triazoles demonstrated excellent activity (MIC, ≤1 μg/ml) against Aspergillus spp. (114 Aspergillus fumigatus, 22 Aspergillus niger, 13 Aspergillus flavus, 9 Aspergillus versicolor, 8 Aspergillus terreus, and 32 Aspergillus spp.): posaconazole (98%), voriconazole (98%), ravuconazole (92%), amphotericin B (89%), and itraconazole (72%). None of the triazoles were active against Fusarium spp. (MIC at which 50% of the isolates tested were inhibited [MIC50], >8 μg/ml) or Mucor spp. (MIC50, >8 μg/ml). Posaconazole and ravuconazole were more active than voriconazole against Rhizopus spp. (MIC50, 1 to 2 μg/ml versus >8 μg/ml, respectively). Based on these results, all three new triazoles exhibited promising activity against Aspergillus spp. and other less commonly encountered isolates of filamentous fungi. The clinical value of these in vitro data remains to be seen, and in vitro-in vivo correlation is needed for both new and established antifungal agents. Surveillance efforts should be expanded in order to monitor the spectrum of filamentous fungal pathogens and their in vitro susceptibility as these new antifungal agents are introduced into clinical use.
Bartnicki-Garcia, S. (Rutgers, the State University, New Brunswick, N. J.), and Walter J. Nickerson. Thiamine and nicotinic acid: Anaerobic growth factors for Mucor rouxii. J. Bacteriol. 82:142–148. 1961.—Mucor rouxii requires preformed thiamine and nicotinic acid for anaerobic growth. Such requirements are not manifested during aerobic incubation. Aerobically, the fungus was shown to be able to synthesize both vitamins.
The yeastlike form and the filamentous form of anaerobically grown M. rouxii exhibit the same vitamin requirements.
Thiamine can be substituted by its thiazole moiety. Under certain conditions, nicotinic acid was partly substituted by tryptophan, kynurenine, 3-hydroxykynurenine, and 3-hydroxyanthranilic acid.
Anaerobically. the fungus (thiamine requiring) was about ten times more susceptible to pyrithiamine antagonism than the same organism grown aerobically (thiamine independent).
We have compared the analytical results obtained by inductively coupled plasma optical emission spectroscopy (ICP-OES) and by scanning electron microscopy with an energy dispersive X-ray analytical system (SEM-EDX) in order to explore the mechanism of metal ions biosorption by biomass using two independent methods. The marine macroalga Enteromorpha sp. was enriched with Cu(II), Mn(II), Zn(II), and Co(II) ions via biosorption, and the biosorption capacity of alga determined from the solution and biomass composition before and after biosorption process was compared. The first technique was used to analyze the composition of the natural and metal-loaded biomass, and additionally the composition of the solution before and after biosorption. The second technique was used to obtain a picture of the surface of natural and metal ion-loaded macroalgae, to map the elements on the cell wall of dry biomass, and to determine their concentration before and after biosorption. ICP-OES showed a better precision and lower detection limit than EDX, but SEM-EDX gave more information regarding the sample composition of Enteromorpha sp. Both techniques confirmed that biosorption is a surface phenomenon, in which alkali and alkaline earth metal ions were exchanged by metal ions from aqueous solution.
FigureThe advantages and disadvantages of ICP-OES and SEM-EDX techniques
Electronic supplementary material
The online version of this article (doi:10.1007/s00604-010-0468-0) contains supplementary material, which is available to authorized users.
Biosorption; Microelement ions; Macroalga Enteromorpha sp.; ICP-OES; SEM-EDX
The biosorption of As(III) on iron-coated fungal biomass of Paecilomyces sp. was studied in this work. It was found that the biomass was very efficient removing the metal in solution, using Atomic Absorption, reaching the next percentage of removals: 64.5%. The highest adsorption was obtained at pH 6.0, at 30°C after 24 hours of incubation, with 1 mg/L of modified fungal biomass.
Beef luncheon meat is one of the most popular meals in several countries in the world including Egypt. Thirty one fungal species and 3 species varieties were recovered from 30 samples of beef luncheon meat collected from different supermarkets in Qena. Alternaria, Aspergillus, Emericella, Mucor, Mycosphaerella, Penicillium and Rhizopus were the most common genera on the two types of media. From the above genera, the most prevalent species were Alternaria alternate, Aspergillus flavus, A. fumigatus, A. niger, A. terreus, Emericella nidulans, Mucor racemosus, Mycosphaerella tassiana, Penicillium chrysogenum and Rhizopus stolonifer. Screening of fungi for their abilities to produce lipase enzyme showed that, ten isolates represented 32.26% of total isolates appeared high lipase production, while sixteen isolates (51.61%) were moderate and 5 isolates (16.13%) were low producers. Aspergillus niger, Fusarium oxysporum and Nectria haematococca produced the highest amount of lipase enzyme, so these fungi were used in further studies. The incorporation of five food preservatives (Disodium phosphate, sodium benzoate, citric acid, potassium sorbate and sodium citrate) individually in the culture medium of lipase production exhibited an inhibitive effect on the mycelial growth and enzyme production by Aspergillus niger, Fusarium oxysporum and Nectria haematococca.
Beef luncheon fungi; Food preservatives; Lipase
The present study is vital to the understanding of bioremediation of structurally different azo dyes by some unusual Brown-rot fungi. Bioremoval of each dye (20 mg l-1) was tested in two different culture media under static and shaking conditions by taking inocula from different fungi. Fungal strains showed varying dyes removal abilities, though considerable high in case of Acid Red (AR) 151(di-azo) as compared to Orange (Or) II (mono-azo). With an exception of Aspergillus tereus SA3, all the fungal isolates showed higher removal of dyes in SDB. Under static condition, the maximum decolorizing fungal strains were; Aspergillus flavus SA2 (67%) and Alternaria spp. SA4 (57%) in AR 151, while Penicillium spp. (34 and 33 %) in Orange II, in SDB and STE, respectively. Bioremoval of dyes was considerably increased when experiments were shifted from static to shaking mode. It was specifically increased (%) in; AR 151 (255) with Penicillium spp., Or II with A. flavus SA2 (112) and Alternaria spp. (111). The primary mechanism of dyes removal proved to be fungal biosorption. However, reduction of dyes (onto fungal) with formation of their products (α. naphthol, sulphalinic acid and aniline) furthermore revealed that dyes (specifically azo) were actually biodegraded.
Azo dyes; Bio-removal; Bio-decolorization; culture conditions; Fungi