Aspergillus hubkae, a Novel Species Isolated from a Patient with Probable Invasive Pulmonary Aspergillosis.

A 50-year-old man, previously diagnosed with pulmonary tuberculosis and lung cavities, presented with symptoms including fever, shortness of breath, and cough. A pulmonary CT scan revealed multiple cavities, consolidation and tree-in-bud in the upper lungs. Further investigation through direct examination of bronchoalveolar lavage fluid showed septate hyphae with dichotomous acute branching. Subsequent isolation and morphological analysis identified the fungus as belonging to Aspergillus section Nigri. The patient was diagnosed with probable invasive pulmonary aspergillosis and successfully treated with a three-month oral voriconazole therapy. Phylogenetic analysis based on partial ß-tubulin, calmodulin and RNA polymerase second largest subunit sequences revealed that the isolate represents a putative new species related to Aspergillus brasiliensis, and is named Aspergillus hubkae here. Antifungal susceptibility testing demonstrated that the isolate is resistant to itraconazole but susceptible to voriconazole. This phenotypic and genetic characterization of A. hubkae, along with the associated case report, will serve as a valuable resource for future diagnoses of infections caused by this species. It will also contribute to more precise and effective patient management strategies in similar clinical scenarios.

Comprehensive health risk assessment of microbial indoor air quality in microenvironments.

The higher airborne microbial concentration in indoor areas might be responsible for the adverse indoor air quality, which relates well with poor respiratory and general health effects in the form of Sick building syndromes. The current study aimed to isolate and characterize the seasonal (winter and spring) levels of culturable bio-aerosols from indoor air, implicating human health by using an epidemiological health survey. Microorganisms were identified by standard macro and microbiological methods, followed by biochemical testing and molecular techniques. Sampling results revealed the bacterial and fungal aerosol concentrations ranging between (300-3650 CFU/m3) and (300-4150 CFU/m3) respectively, in different microenvironments during the winter season (December-February). However, in spring (March-May), bacterial and fungal aerosol concentrations were monitored, ranging between (450-5150 CFU/m3) and (350-5070 CFU/m3) respectively. Interestingly, Aspergillus and Cladosporium were the majorly recorded fungi whereas, Staphylococcus, Streptobacillus, and Micrococcus found predominant bacterial genera among all the sites. Taken together, the elevated levels of bioaerosols are the foremost risk factor that can lead to various respiratory and general health issues in additional analysis, the questionnaire survey indicated the headache (28%) and allergy (20%) were significant indoor health concerns. This type of approach will serve as a foundation for assisting residents in taking preventative measures to avoid exposure to dangerous bioaerosols.

The accuracy and clinical impact of the morphological identification of Aspergillus species in the age of cryptic species: A single-centre study.

BACKGROUND: Aspergillus spp. is identified morphologically without antifungal susceptibility tests (ASTs) in most clinical laboratories. The aim of this study was to examine the clinical impact of the morphological identification of Aspergillus spp. to ensure the adequate clinical management of Aspergillus infections. PATIENTS/METHODS: Aspergillus isolates (n = 126) from distinct antifungal treatment-naïve patients with aspergillosis were first identified morphologically, followed by species-level identification via DNA sequencing. An AST for itraconazole (ITC) and voriconazole (VRC) was performed on each Aspergillus isolate. RESULTS: Based on the genetic test results, morphology-based identification was accurate for >95% of the isolates at the species sensu lato level although the test concordance of Aspergillus spp. with low detection rates was low. The rates of cryptic species were found to be 1.2% among the isolates of A. fumigatus complex and 96.8% in the A. niger complex. Cryptic species with lower susceptibilities to antifungal drugs than sensu stricto species among the same Aspergillus section were as follows: The A. lentulus (n = 1) isolates had low susceptibilities to azoles among the A. fumigatus complex species (n = 86), and A. tubingensis isolates (n = 18) exhibited lower susceptibility to azoles among the A. niger complex species (n = 31). CONCLUSION: Diagnostic accuracy was high at the A. fumigatus and A. niger complex level. However, in the presence of cryptic species, a solely morphological identification was insufficient. Particularly, ITC and VRC might be inappropriate for aspergillosis treatment when the A. niger complex is identified morphologically because it is possible that the Aspergillus isolate is A. tubingensis.

Óleo essencial de Pataqueira (Conobea scoparioides Cham. & Schltdl.) como conservante natural em Cosméticos / Pataqueira essential oil (Conobea scoparioides Cham. & Schltdl.) as a natural preservative in cosmetics

Um dos principais grupos de conservantes utilizados na maioria dos cosméticos são os parabenos que em muitos estudos demonstraram que podem provocar reações alérgicas como dermatite de contato, entre outras sensibilizações cutâneas. A fim de minimizar esses problemas, a indústria está produzindo cosméticos livres de conservantes ou de origem natural e em associações aos sintéticos. Dentre os conservantes naturais utilizados, podemos citar os óleos essenciais como uma alternativa viável. Diante deste contexto o presente trabalho visa avaliar experimentalmente o potencial antimicrobiano do óleo essencial de Conobea scoparioides Cham. & Schltdl., conhecida popularmente como pataqueira, o efeito de sua associação com parabenos e de sua eficácia como conservante em bases cosméticas. A composição do óleo essencial foi avaliada, indicando que este é composto em sua maior parte por terpenos, tendo éter metílico do timol (39,2%), timol (33,8 %) e α-felandreno (15,9%) como compostos majoritários. A atividade antimicrobiana do óleo essencial e do timol foi acessada através da concentração inibitória mínima (CIM), cujos resultados em µg/mL para o óleo essencial e o timol foram respectivamente: Staphylococcus aureus 650,70 e 284,90, Escherichia coli 721,53 e 271,20, Pseudomonas aeruginosa 1748,00 e > 2.000, Burkholderia cepacia 833,03 e 1.077,70, Candida albicans 521,43 e 172,61 e Aspergillus brasiliensis 300 e 400. O efeito sinérgico da associação do óleo essencial com os parabenos foi realizado através de um delineamento experimental centroide simplex para uma mistura de metilparabeno, propilparabeno e óleo essencial frente aos mesmos micro-organismos utilizados na determinação da atividade antimicrobiana. As concentrações ideais obtidas pela análise estatística para cada componente em µg/mL foram: 1120 para o metilparabeno, 350 para o propilparabeno e 675 para o óleo essencial. O teste de eficácia do sistema conservante em formulação cosmética foi efetuado empregando as concentrações ideais e mais duas concentrações superiores e uma abaixo do ideal. Para todas as cepas microbianas desafiadas o resultado do teste foi de redução total da carga microbiana inoculada nos sete dias de ensaio e nenhum aumento até o vigésimo oitavo dia o que demonstra a eficácia da associação do óleo essencial com os conservantes sintéticos. O óleo essencial de C. scoparioides apresentou um potencial antimicrobiano importante tanto sozinho como em associação com conservantes sintéticos. Estes resultados sugerem que esse óleo pode ser usado para compor um sistema conservante para formulações cosméticas contendo uma menor quantidade de sintéticos

One of the main groups of preservatives used in most cosmetics are parabens, that many studies have shown that they can cause allergic reactions such as contact dermatitis, among other skin sensitizations. To minimize these problems, the industry is producing cosmetics preservative free or using natural products instead and their combination with the synthetics. Among the natural preservatives used, we can mention essential oils as a viable alternative. In this context, the present work aims to experimentally evaluate the antimicrobial potential of the Conobea scoparioides Cham. & Schltdl. essential oil, popularly known as pataqueira, the effect of its association with parabens and its effectiveness as a preservative in cosmetic bases. The essential oil composition was analyzed, indicating that it is composed mostly of terpenes, with thymol methyl ether (39.2%), thymol (33.8%) and -phelandrene (15.9%) as major compounds. The antimicrobial activity of essential oil and thymol was accessed through the minimum inhibitory concentration (MIC), whose results in µg/mL for essential oil and thymol were respectively: Staphylococcus aureus 650.70 and 284.90, Escherichia coli 721, 53 and 271.20, Pseudomonas aeruginosa 1748.00 and > 2,000, Burkholderia cepacia 833.03 and 1,077.70, Candida albicans 521.43 and 172.61 and Aspergillus brasiliensis 300 and 400. The synergistic effect of the association of essential oil with parabens was performed through a centroid simplex experimental design for a mixture of methylparaben, propylparaben and essential oil against the same microorganisms used in the antimicrobial activity evaluation The ideal concentrations obtained by statistical analysis for each component in µg/mL were: 1120 for methylparaben, 350 for propylparaben and 675 for essential oil. The effectiveness test of the preservative system in cosmetic formulation was carried out using the ideal concentrations plus two higher concentrations and one below the ideal. For all challenged microbial strains, the test result was a total reduction of the inoculated microbial load in the seven days of testing and no increase until the twenty-eighth day, which demonstrates the effectiveness of the association of essential oil with synthetic preservatives. C. scoparioides essential oil showed an important antimicrobial potential both alone and in association with parabens. These results demonstrated that it can be used to compose a preservative system for cosmetic formulations containing lower amounts of synthetics

Molecular typing and antifungal susceptibility study of Aspergillus spp. in intensive care unit (ICU) patients in Indonesia.

INTRODUCTION: Aspergillus exhibits a wide variation of susceptibility against antifungals according to genetic and environmental factors. Identification to the species level is necessary for appropriate treatment. Our objective was to determine the Aspergillus species involved in invasive pulmonary aspergillosis (IPA) among ICU patients in Jakarta, Indonesia. METHODOLOGY: The incidence of IPA in ICU patients at six hospitals in Jakarta from October 2012 - January 2015 was investigated. It involved a collection of endotracheal aspirates (ETA), nasal swabs and environmental samples around the hospitals, phenotypic screening, molecular characterization, and antifungal susceptibility testing. RESULTS: Of the 405 patients investigated, 31 patients (7.7%) were diagnosed with putative IPA, from whom 45 Aspergillus isolates were collected. Aspergillus isolates were identified from pulmonary secretions in 24 patients, from nasal swabs in 7 patients and from both pulmonary secretions and nasal swabs in 7 patients. The phenotypic method showed 33 isolates of Aspergillus flavus (73.4%), nine Aspergillus fumigatus (20%), two Aspergillus niger (4.4%), and one Aspergillus nidulans (2.2%) isolate. Molecular identification showed 27 isolates of A. flavus (60.0%), eight isolates of A. fumigatus (17.8%), two isolates of A. niger (4.4%) and one isolate of A. nidulans (2.2%), while seven isolates (15.6%) were cryptic species or mixed isolates. CONCLUSIONS: Susceptibility testing showed all isolates were susceptible to amphotericin B, azoles and micafungin. Aspergillus flavus was the main causative organism in IPA cases in Jakarta, followed by A. fumigatus.

Invasive aspergillosis due to Aspergillus cryptic species: A prospective multicentre study.

OBJECTIVES: Aspergillus cryptic species are increasingly recognised causes of Aspergillus diseases, including life-threatening invasive aspergillosis (IA). However, as their accurate identification remains challenging in a routine practice, few is known from a clinical and epidemiological perspective. Recently, the MSI application has emerged as a powerful tool for the detection and identification of Aspergillus cryptic species. We aimed to use to the network of users of the MSI application to conduct a multicentre prospective screening of Aspergillus cryptic species-related IA and analyse their epidemiological, clinical and mycological characteristics. METHODS: Over a 27-month period, the clinical involvement of 369 Aspergillus cryptic isolates, from 13 French and Danish MSI application users, was prospectively analysed. Species identification was confirmed by DNA-sequencing and antifungal susceptibility testing was performed using EUCAST reference method. Fifty-one A fumigatus sensu stricto invasive cases were also analysed. RESULTS: Fifteen cryptic isolates were responsible of IA. Eight species were involved, including 5 cases related to the species A sublatus. These species showed high rate of in vitro low susceptibility to antifungal drugs. In comparison with A fumigatus sensu stricto invasive cases, pre-exposure to azole drugs was significantly associated with cryptic IA (P = .02). DISCUSSION: This study brings new insights in cryptic species related IA and underlines the importance to identify accurately at the species level these Aspergillus isolates. The increasing use of antifungal drugs might lead in the future to an epidemiologic shift with an emergence of resistant isolates involved in IA.

Interspecific evolutionary relationships of alpha-glucuronidase in the genus Aspergillus.

The increased availability and production of lignocellulosic agroindustrial wastes has originated proposals for their use as raw material to obtain biofuels (ethanol and biodiesel) or derived products. However, for biomass generated from lignocellulosic residues to be successfully degraded, in most cases it requires a physical (thermal), chemical, or enzymatic pretreatment before the application of microbial or enzymatic fermentation technologies (biocatalysis). In the context of enzymatic technologies, fungi have demonstrated to produce enzymes capable of degrading polysaccharides like cellulose, hemicelluloses and pectin. Because of this ability for degrading lignocellulosic material, researchers are making efforts to isolate and identify fungal enzymes that could have a better activity for the degradation of plant cell walls and agroindustrial biomass. We performed an in silico analysis of alpha-glucoronidase in 82 accessions of the genus Aspergillus. The constructed dendrograms of amino acid sequences defined the formation of 6 groups (I, II, III, IV, V, and VI), which demonstrates the high diversity of the enzyme. Despite this ample divergence between enzyme groups, our 3D structure modeling showed both conservation and differences in amino acid residues participating in enzyme-substrate binding, which indicates the possibility that some enzymes are functionally specialized for the specific degradation of a substrate depending on the genetics of each species in the genus and the condition of the habitat where they evolved. The identification of alpha-glucuronidase isoenzymes would allow future use of genetic engineering and biocatalysis technologies aimed at specific production of the enzyme for its use in biotransformation.

Aspergillus section Flavi and aflatoxins in Brazilian cassava (Manihot esculenta Crantz) and products.

Aflatoxins are carcinogenic compounds produced by some species of Aspergillus, especially those belonging to Aspergillus section Flavi. Their occurrence in food may start in the field, in the post-harvest, or during storage due to inadequate handling and storage. Because cassava is a staple food for a high percentage of the Brazilian population, we evaluated the presence of aflatoxin-producing species in cassava tubers, cassava products (cassava flour, cassava starch, sour starch, and tapioca flour), and in soil samples collected from cassava fields. In addition, the levels of aflatoxin contamination in cassava products were quantified. A total of 101 samples were analyzed, and 45 strains of Aspergillus section Flavi were isolated. Among the identified species, Aspergillus flavus, Aspergillus arachidicola, Aspergillus novoparasiticus, and Aspergillus parasiticus were found. The majority of strains (73.3%) tested for their aflatoxin-producing ability in synthetic media was positive. Despite that, cassava and cassava products were essentially free of aflatoxins, and only one sample of cassava flour contained traces of AFB1 (0.35 µg/kg).

Microevolution in the pansecondary metabolome of Aspergillus flavus and its potential macroevolutionary implications for filamentous fungi.

Fungi produce a wealth of pharmacologically bioactive secondary metabolites (SMs) from biosynthetic gene clusters (BGCs). It is common practice for drug discovery efforts to treat species' secondary metabolomes as being well represented by a single or a small number of representative genomes. However, this approach misses the possibility that intraspecific population dynamics, such as adaptation to environmental conditions or local microbiomes, may harbor novel BGCs that contribute to the overall niche breadth of species. Using 94 isolates of Aspergillus flavus, a cosmopolitan model fungus, sampled from seven states in the United States, we dereplicate 7,821 BGCs into 92 unique BGCs. We find that more than 25% of pangenomic BGCs show population-specific patterns of presence/absence or protein divergence. Population-specific BGCs make up most of the accessory-genome BGCs, suggesting that different ecological forces that maintain accessory genomes may be partially mediated by population-specific differences in secondary metabolism. We use ultra-high-performance high-resolution mass spectrometry to confirm that these genetic differences in BGCs also result in chemotypic differences in SM production in different populations, which could mediate ecological interactions and be acted on by selection. Thus, our results suggest a paradigm shift that previously unrealized population-level reservoirs of SM diversity may be of significant evolutionary, ecological, and pharmacological importance. Last, we find that several population-specific BGCs from A. flavus are present in Aspergillus parasiticus and Aspergillus minisclerotigenes and discuss how the microevolutionary patterns we uncover inform macroevolutionary inferences and help to align fungal secondary metabolism with existing evolutionary theory.

Aspergillosis: Epidemiology, Diagnosis, and Treatment.

The spectrum of disease produced by Aspergillus species ranges from allergic syndromes to chronic pulmonary conditions and invasive infections. Invasive aspergillosis is a major cause of morbidity and mortality in immunocompromised patients. Risk factors continue to evolve and include newer biological agents that target the immune system and postinfluenza infection; and it has been observed following COVID-19 infection. Diagnosis remains a challenge but non-culture-based methods are available. Antifungal resistance has emerged. Voriconazole remains the treatment of choice but isavuconazole and posaconazole have similar efficacy with less toxicity. Combination therapy is used with extensive infection and in severe immunosuppression.

Eurotium cristatum Fermented Loose Dark Tea Ameliorates Cigarette Smoke-Induced Lung Injury by MAPK Pathway and Enhances Hepatic Metabolic Detoxification by PXR/AhR Pathway in Mice.

Cigarette smoke- (CS-) induced oxidative stress and inflammation in the lung are serious health problems. Primary and reprocessed tea products contain multiple antioxidants that have been reported to protect the lung against CS-induced injury. However, the beneficial effects of Eurotium cristatum fermented loose dark tea (ECT) and Eurotium cristatum particle metabolites (ECP) on CS-induced lung injury and its potential hepatic metabolic detoxification are still unclear. Therefore, sixty mice were randomly divided into six equal groups. CS-exposed mice were prevented or treated with ECP or ECT infusions for 12 or 8 weeks to determine the antioxidative stress, anti-inflammatory and potential metabolic detoxification of ECT and ECP. Thirty-six mice were randomly divided into six equal groups to observe the effects on hepatic metabolic detoxification by replacing daily drinking water with ECT. Results showed that CS significantly decreased the activities of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) and upregulated the expressions of malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), IL-8, and IL-1ß in serum. These adverse effects were modulated by ECP and ECT. In addition, ECT upregulated the mRNA expression of pregnane X receptor (PXR) and cytochrome P450 (CYP450) in the liver on daily free drinking ECT mice group. Western blot analysis further revealed that in CS-exposed mice, ECP and ECT significantly decreased the phosphorylation of mitogen-activated protein kinase (MAPK) in the lung but upregulated the protein expressions of PXR and aryl hydrocarbon receptor (AhR) in the liver. Overall, our findings demonstrated that ECT and ECP protected against lung injury induced by CS via MAPK pathway and enhanced hepatic metabolic detoxification via PXR and AhR pathways. Therefore, daily intake of ECT and ECP can potentially protect against CS-induced oxidative and inflammatory injuries.

DNA barcoding of phytopathogens for disease diagnostics and bio-surveillance.

DNA barcoding has proven to be a versatile tool for plant disease diagnostics in the genomics era. As the mass parallel and next generation sequencing techniques gained importance, the role of specific barcodes came under immense scrutiny. Identification and accurate classification of phytopathogens need a universal approach which has been the main application area of the concept of barcode. The present review entails a detailed description of the present status of barcode application in plant disease diagnostics. A case study on the application of Internal Transcribed Spacer (ITS) as barcode for Aspergillus and Fusarium spp. sheds light on the requirement of other potential candidates as barcodes for accurate identification. The challenges faced while barcoding novel pathogens have also been discussed with a comprehensive outline of integrating more recent technologies like meta-barcoding and genome skimming for detecting plant pathogens.

Species distribution and antifungal susceptibility of Aspergillus clinical isolates in Lebanon.

Aim: We sought to provide first insights into the epidemiology and antifungal susceptibility patterns of the aspergilli in Lebanon. Materials & methods: After species identification, antifungal susceptibility was investigated according to EUCAST recommendations. CYP51A gene was sequenced in resistant isolates and its expression level was evaluated by Reverse transcription-quantitative PCR. Results: Among the 73 Aspergillus isolates studied (mostly from ears), the predominant species was Aspergillus niger (54.8%). The overall drug resistance was highest for amphotericin B (38.4%), followed by itraconazole (31.5%), posaconazole (30.1%) and voriconazole (23.3%). In addition, CYP51A gene mutations were not the major cause of azole resistance among these isolates. Conclusion: Our findings indicate the paramount need for an integral One Health strategy and a national reference center for invasive mycoses and antifungals.

Aspergillus collected in specific indoor settings: their molecular identification and susceptibility pattern.

Exposure to Aspergillus conidia is an increased risk factor for the development of respiratory symptoms. The emergence of azole resistance in Aspergillus fumigatus is a major concern for the scientific community. The aim of this study was to perform the molecular identification of Aspergillus species collected from different occupational and non-occupational indoor settings and to study the azole susceptibility profile of the collected Fumigati isolates. The selected Aspergillus isolates were identified as belonging to the sections Fumigati, Nigri Versicolores, Terrei, Clavati and Nidulantes. All the Aspergillus fumigatus were screened for azole resistance using an agar media supplemented with itraconazole, voriconazole and posaconazole. None of the tested isolates showed resistance to those azoles. Knowledge of Aspergillus epidemiology in specific indoor environments allows a better risk characterization regarding Aspergillus burden. This study allowed the analysis of the molecular epidemiology and the determination of the susceptibility pattern of Aspergillus section Fumigati found in the studied indoor settings.

Phylogenetic diversity and prevalence of mycoflora in ready-to-eat supermarket and roadside-vended peanuts.

Little is known of the mycobiota present in ready-to-eat peanuts consumed in Southern Africa. Knowledge of the mycobiota and aflatoxigenic species can elucidate potential health risks associated with consumption of ready-to-eat peanuts sold by supermarkets and roadside vendors. We investigated the culturable mycobiota diversity in supermarket and roadside-vended peanuts as well as the presence of five aflatoxin biosynthesis pathway-related genes (aflR, aflJ, aflM, aflD, and aflP) in 15 suspected aflatoxigenic isolates, with a focus on Mafikeng, South Africa. Mean colony-forming unit (CFU) counts of 288.7 and 619.7 CFU/g were observed in supermarket and roadside-vended peanuts, respectively. A total of 145 fungal isolates comprising 26 distinct taxa (based on 97% internal transcribed spacer region [ITS1-5.8S-ITS2] sequence similarity) were obtained, including strains representing Aspergillus, Acremonium, Alternaria, Bipolaris, Chaetomium, Ectophoma, Epicoccum, Hamigera, Leancillium, Monascus, Penicillium, Periconia, Talaromyces, and Trichoderma. Phylogenetic analyses of concatenated sequences of the ITS1-5.8S-ITS2, ß-tubulin, and calmodulin genes delineated the species of Aspergillus, which included A. flavus, A. fumigatus, A. hiratsukae, A. niger, and A. parasiticus. Higher species richness was obtained from supermarket peanuts compared with roadside-vended peanuts, with eight species common to both sources. Across supermarket or roadside-vended peanuts, A. fumigatus, A. niger, and A. flavus were prevalent (>40% incidence). In contrast, strains related to or representing Ectophoma multirostata, Aspergillus hiratsukae, Bipolaris zeae, Chaetomium bostrychodes, Epicoccum nigrum, Hamigera paravellanea, Lecanicillium aphanocladii, Monascus ruber, Periconia macrospinosa, Periconia lateralis, Talaromyces funiculosus, Talaromyces minioluteus, Talaromyces wortmannii, Talaromyces spp., and Trichoderma sp. were detected in either supermarket or roadside-vended peanuts. Among the five aflatoxin biosynthesis pathway-related genes, aflD and aflM were more prevalent (87%) and aflR was the least prevalent (40%). Findings suggest that roasted peanuts meant for human consumption and sold at supermarkets and by roadside vendors are contaminated with potential toxin-producing fungi. Hence, proper processing and packaging of peanuts before vending is recommended.

New morphological criteria and molecular characterization of black aspergilli aggregate from corn, sorghum and wheat grains.

Corn, sorghum and wheat grains are used as livestock feed in the world. Identification of black aspergilli associated with these grains is necessary to make sure of the safety of the grains because its occurrence is an indicator of mycotoxin production. Forty-five isolates were isolated from the samples collected from Upper Egypt's markets and identified morphologically based on colony color, conidia, stipe and vesicle size and molecularly by using ß-tubulin and calmodulin genes. Isolates were divided into 30 strains of Aspergillus welwitschiae and 15 strains of A. niger. We have found new criteria in the morphological identification of A. welwitschiae as its colony color was black to brown with yellow edge, but in A. niger was black with white edge, also A. welwitschiae sometimes produced finely-to-distinctly roughened brownish conidia on malt extract agar (MEA) media. Thirteen isolates of A. welwitschiae and six of A. niger were recognized as potential producers for ochratoxin A.

Identification and iterative combinatorial mutagenesis of a new naringinase-producing strain, Aspergillus tubingensis MN589840.

Naringinase was mainly obtained by microbial fermentation, and mutagenesis was a major way for obtaining excellent mutants. The aim of this study was to screen out a high naringinase yielding mutant to enhance the potential application value of its industrialization and compare the effects of different mutagenic methods on the enzyme activity of the strain. A novel producing naringinase strain, Aspergillus tubingensis MN589840, was isolated from mildewed pomelo peel, later subjected to mutagenesis including UV, ARTP and UV-ARTP. After five rounds iterative mutagenesis, the mutants U1, A6 and UA13 were screened out with 1448·49, 1848·71, 2475·16 U mg-1 enzyme activity, the naringinase productivity raised by 79·08, 123·56 and 206%, respectively. In addition, the naringinase activity of three mutants rose after each round of iterative mutagenesis. These results indicated that the mutagenesis efficiency of UV-ARTP was higher than that of single ARTP, and both are better than UV. In summary, the iterative UV-ARTP mutagenesis is an effective strategy for screening high naringinase-producing strains.

Black aspergilli in Brazilian onions: From field to market.

The occurrence of black aspergilli in onions has been reported as frequent, and this group of fungi harbors potentially toxigenic species. In addition, Aspergillus niger has been reported as the causative agent of black mold rot, an important postharvest disease that causes damage throughout the world. Brazil stands out as one of the world's largest onion producers. However, few studies have been conducted to investigate the mycobiota in Brazilian onions. For this reason, we investigated the mycobiota of 48 market (n = 25) and field (n = 23) onion bulb samples. Nineteen soil samples were collected from the same fields and evaluated. In field onions and soil samples, Penicillium spp. was the prevalent fungal group, whereas in market samples A. section Nigri was the most frequent group. Due to the taxonomic complexity of this group, species identification was supported by phylogenetic data (CaM gene). A. welwitschiae was the most prevalent species in market samples. Black aspergillus strains were evaluated for fumonisin B2 (FB2) and ochratoxin A (OTA) production. Overall, 53% and 2.2% of the strains produced FB2 and OTA, respectively. The occurrence of FB2 and OTA was also investigated in onion bulb samples but none showed contamination with these mycotoxins.

Living in the dark: Bat caves as hotspots of fungal diversity.

Bat caves are very special roosts that harbour thousands of bats of one or more species. Such sites may hold an incredible "dark fungal diversity" which is still underestimated. We explored the culturable fungal richness in the air, on bats, and in the guano in a bat cave in Brazil's Caatinga dry forest. Fungal abundance was 683 colony-forming units (CFU) in the guano, 673 CFU in the air, and 105 CFU on the bats. Based on morphological and phylogenetic analysis of ITS, LSU, and TUB2 sequences, fungal isolates of 59 taxa belonging to 37 genera in the phyla Ascomycota (28 genera, including Aspergillus, Penicillium, Cladosporium, and Talaromyces), Basidiomycota (eight genera, including Rhodotorula and Schizophyllum), and Mucoromycota (only Rhizopus) were identified. The fungal richness in the air was 23 taxa (especially Aspergillus taxa), mainly found at 15 m and 45 m from the cave entrance; on the bodies of bats it was 36 taxa (mainly Aspergillus taxa), especially on their wing membranes (21 taxa, nine of which were exclusively found in this microhabitat); and in guano 10 fungal taxa (especially Aspergillus and Penicillium) were found. The fungal richness associated with guano (fresh and non-fresh) was similar from bats with different eating habits (insectivorous, frugivorous, and haematophagous). Sampling effort was not sufficient to reveal the total fungal taxa richness estimated. Eight (21.6%) of the 37 genera and 17 (53.1%) of the 32 identified fungal species are reported for the first time in caves. Our results highlight bat caves in Brazil as hotspots of fungal diversity, emphasizing the need to protect such special roosts.

Identifying candidate Aspergillus pathogenicity factors by annotation frequency.

BACKGROUND: Members of the genus Aspergillus display a variety of lifestyles, ranging from saprobic to pathogenic on plants and/or animals. Increased genome sequencing of economically important members of the genus permits effective use of "-omics" comparisons between closely related species and strains to identify candidate genes that may contribute to phenotypes of interest, especially relating to pathogenicity. Protein-coding genes were predicted from 216 genomes of 12 Aspergillus species, and the frequencies of various structural aspects (exon count and length, intron count and length, GC content, and codon usage) and functional annotations (InterPro, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes terms) were compared. RESULTS: Using principal component analyses, the three sets of functional annotations for each strain were clustered by species. The species clusters appeared to separate by pathogenicity on plants along the first dimensions, which accounted for over 20% of the variance. More annotations for genes encoding pectinases and secondary metabolite biosynthetic enzymes were assigned to phytopathogenic strains from species such as Aspergillus flavus. In contrast, Aspergillus fumigatus strains, which are pathogenic to animals but not plants, were assigned relatively more terms related to phosphate transferases, and carbohydrate and amino-sugar metabolism. Analyses of publicly available RNA-Seq data indicated that one A. fumigatus protein among 17 amino-sugar processing candidates, a hexokinase, was up-regulated during co-culturing with human immune system cells. CONCLUSION: Genes encoding hexokinases and other proteins of interest may be subject to future manipulations to further refine understanding of Aspergillus pathogenicity factors.