Despite recent advances in down-stream processing, production of microalgae remains substantially limited because of economical reasons. Harvesting and dewatering are the most energy-intensive ...processing steps in their production and contribute 20-30% of total operational cost. Bio-flocculation of microalgae by co-cultivation with filamentous fungi relies on the development of large structures that facilitate cost effective harvesting. A yet unknown filamentous fungus was isolated as a contaminant from a microalgal culture and identified as Isaria fumosorosea. Blastospores production was optimized in minimal medium and the development of pellets, possibly lichens, was followed when co-cultured with Chlorella sorokiniana under strict autotrophic conditions. Stable pellets (1-2mm) formed rapidly at pH 7-8, clearing the medium of free algal cells. Biomass was harvested with large inexpensive filters, generating wet slurry suitable for hydrothermal gasification. Nutrient rich brine from the aqueous phase of hydrothermal gasification supported growth of the fungus and may increase the process sustainability.
Chemical warfare including insecticidal secondary metabolites is a well‐known strategy for environmental microbes to monopolize a food source. Insects in turn have evolved behavioural and ...physiological defences to eradicate or neutralize the harmful microorganisms. We studied the defensive repertoire of insects in this interference competition by combining behavioural and developmental assays with whole‐transcriptome time‐series analysis. Confrontation with the toxic filamentous fungus Aspergillus nidulans severely reduced the survival of Drosophila melanogaster larvae. Nonetheless, the larvae did not behaviourally avoid the fungus, but aggregated at it. Confrontation with fungi strongly affected larval gene expression, including many genes involved in detoxification (e.g., CYP, GST and UGT genes) and the formation of the insect cuticle (e.g., Tweedle genes). The most strongly upregulated genes were several members of the insect‐specific gene family Osiris, and CHK‐kinase‐like domains were over‐represented. Immune responses were not activated, reflecting the competitive rather than pathogenic nature of the antagonistic interaction. While internal microbes are widely acknowledged as important, our study emphasizes the underappreciated role of environmental microbes as fierce competitors.
Abstract Fungi exhibit three adverse effects on human health: inflammatory, allergic and toxic effects, these implications affect mainly immunodepressed patients. The objective of this work was to ...analyze the fungal microbiota of the ambient air of an Intensive Care Unit. Three collections were carried out in an Intensive Care Unit in the city of Rio Branco, Acre, Western Amazon, Brazil from March to May 2017. 126 Petri dishes were exposed with the culture medium Agar Sabouraud with chloramphenicol and Agar Mycosel, considering the distribution of the 21 air conditioners, split residential model. The plates were incubated for seven days at room temperature and the growth of Colony Forming Units was observed. Colony counting and isolation for the morphological characterization of the granted fungi was performed. After quantification, the concentration of fungi per cubic meters of air (CFU.m-3) was settled. The third collection had a larger number of colony forming units with 48.6%. In the total of the analyzed samples, filamentous fungi (85.5%) and yeasts (14.5%) were isolated. Thirteen genera of fungi were identified, with the most frequent filaments being Cladosporium spp. 33.0%, Aspergillus spp. 30.4% and Penicillium spp. 19.6%, and yeasts Candida spp. 52.6%, Trichosporon spp. 36.9%. The colony-forming unit per cubic meter (CFU.m-3) did not shown any difference between the Cores in the same collection period, however in the 1st and 3rd collection, Core 1 had the highest average. The fungal microbiota of this Unit presented thirteen different genera potentially pathogenic, revealing the need for monitoring microorganisms and prevention actions.
Resumo Os fungos exibem três efeitos adversos para a saúde humana: inflamatórios, alérgicos e tóxicos, esses efeitos atingem principalmente pacientes imunodeprimidos. O objetivo do trabalho foi analisar a microbiota fúngica do ar ambiente em uma Unidade de Terapia Intensiva na cidade de Rio Branco, Acre, Amazônia Ocidental, Brasil. Foram realizadas 03 coletas em uma Unidade de Terapia Intensiva na cidade de Rio Branco, Acre, Amazônia Ocidental, Brasil no período de março a maio de 2017. Foram expostas 126 placas de Petri com os meios de cultura Ágar Sabouraud com cloranfenicol e Ágar Mycosel, considerando a distribuição dos 21 condicionadores de ar, modelo split residencial. As placas foram incubadas por sete dias em temperatura ambiente e observado o crescimento das Unidades Formadoras de Colônias. A contagem de colônias e o isolamento para a caracterização morfológica dos fungos isolados foi realizada. Após a quantificação, foi calculada a concentração de fungos por metros cúbicos de ar (UFC.m-3). A terceira coleta teve maior quantidade de unidades formadoras de colônias com 48,6%. No total das amostras analisadas, foram isolados fungos filamentosos (85,5%) e leveduriformes (14,5%). Foram identificados 13 gêneros de fungos, sendo os filamentosos mais frequentes Cladosporium spp. 33,0%, Aspergillus spp. 30,4% e Penicillium spp. 19,6% e os leveduriformes Candida spp. 52,6%, Trichosporon spp. 36,9%. A unidade formadora de colônia por metros cúbicos (UFC.m-3) não houve diferença entre os Núcleos no mesmo período de coleta, porém na 1ª e 3ª coleta, o Núcleo 1 apresentou maior média. A microbiota fúngica desta Unidade apresentou treze gêneros diferentes potencialmente patogênicos, mostra a necessidade de monitoramento dos microrganismos e ações de prevenção.
Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a powerful technique for the identification of microorganisms. The technique normally requires a sample ...preparation procedure before instrumental analysis, which can be somewhat labor-intensive when numbers of samples are large. The direct smear method, in which samples are directly smeared on the sample plates and subsequently subjected to instrumental analyses, can save time and is less labor-intensive. However, the method has rarely been tested on filamentous fungi, although it has been successfully used in the identification of bacteria and yeasts. In the present study, we examined the method using clinically-collected filamentous fungi.
Three hundred forty-eight isolates of filamentous fungi representing 9 species collected from body fluids of patients were analyzed on the VITEK MS version 3.0 system, a popular commercial MALDI-TOF MS system, using the direct smear method. For those misidentified or unidentified, the samples were retested. All fungal species were determined through DNA sequencing.
Among 334 isolates that were included in the database of the VITEK system, 286 (85.6%) samples were correctly identified. After retesting, the rate of correct identification increased to 91.0%. Aspergillus fumigatus exhibited a 95.2% rate of correct identification before retesting, whereas Aspergillus niger showed the rate at only 46.5% (58.1% even with retesting).
The direct smear method could be used in the identification of filamentous fungi found in body fluids of patients by MALDI-TOF MS at good rates of correct identification. The method is simple and time-saving, and deserves further evaluation.
•Extracellular peptidases can serve as markers of ecological features of fungi.•Asco- and basidiomycetes secrete mainly serine and metallopeptidases, respectively.•The species of pathogenic fungi ...secrete trypsin-like peptidases.•The role of secreted enzymes in proteolysis depends on community composition.
Fungi produce extracellular peptidases to break down proteins and polypeptides into smaller soluble molecules. These molecules are subsequently transported into the fungal cell, supplying osmotrophic nutrition. Although a variety of extracellular peptidases have been isolated from numerous fungal species, it remains largely unknown how the spectrum of secreted peptidases correlates with fungal ecology and taxonomy. In this study, we cultivated 17 fungal species on protein-enriched medium to compare the spectra of secreted peptidases produced by the fungi belonging to different ecological groups (pathogens, saprotrophs, symbionts) and taxonomic phyla (Ascomycota and Basidiomycota). Basidiomycetes predominantly produced metallopeptidases with neutral pH optima, while the species of ascomycetes secreted serine peptidases with alkaline pH optimum, mostly of the subtilisin-type. Fungal species with dominant activity of serine peptidases had, in general, much higher peptidase activity and were better adapted to growth on protein medium compared to the species with dominant metallopeptidase activity. Pathogenic fungi effectively cleaved the synthetic substrate specific for trypsin-like peptidases, while saprotrophic species were characterized by a relatively high aminopeptidase activity. Nevertheless, fungi have numerous genes encoding various types of peptidases, the spectra of fungal enzymes secreted on cultivation medium were to a major extent represented by the production of one class of peptidases that correlated with fungal taxonomic phylum. We suppose fungal strategies for cleaving polypeptides in experimental conditions are largely predetermined both by trophic status and phylogeny.
Opportunistic fungi are those that normally would not cause diseases in otherwise healthy people, but are able to cause problems under some circumstances, and for this they need to possess a certain ...virulence potential. The objective of this study was to identify samples of filamentous fungi isolated from poultry barns in Cascavel, Paraná, and also to evaluate their virulence potential by assessing proteinase production, hemolytic activity, urease production, and growth rate at 37 ºC. We have evaluated the following samples: Acremonium hyalinulum (1 sample), Aspergillus sp. (12), Beauveria bassiana (1), Curvularia brachyspora (1), Paecilomyces variotti (1), and Penicillium sp. (2). Out of the 18 samples analyzed, 44.4% showed proteolytic activity using albumin as the substrate versus 66.7% when using casein; 66.7% showed hemolytic activity, 83.3% were positive for urea, and 88.9% grew at a temperature of 37 ºC. The results demonstrated that the majority of the isolates expressed virulence factors. Therefore, these isolates have the potential to harm human hosts, such as those working at poultry barns, especially predisposed or susceptible individuals.
Aqueous organic redox flow batteries (AORFBs) have gained increased interest as a promising solution to store energy from sustainable energy sources. Inspired by naturally occurring bio‐quinones, we ...here propose a new electrolyte based on the fungal compound phoenicin. Phoenicin was produced using the filamentous fungus Penicillium atrosanguineum at a concentration of 1.24 g L−1 liquid medium and extracted using ethyl acetate to a purity exceeding 95 %. The fungus may provide a benefit of high scalability of the biosynthesis‐based production of the electroactive substance. Here, we demonstrate the performance of biologically produced phoenicin as a negative electrolyte in an RFB against ferro/ferricyanide, as a proof of concept, giving an initial capacity of 11.75 Ah L−1 and a capacity decay of 2.85 % day−1. For a deeper investigation of the battery setup, in situ attenuated total reflection infrared (ATR‐IR) spectra of the phoenicin electrolyte were recorded. Symmetric cell cycling was performed to study the stability of this bio‐based active material.
Biobased: The filamentous fungus can be used as an environmentally and sustainable benign source to produce the bio‐based quinone phoenicin. This natural compound shows electrochemical properties, which can be used as the active material in the negative electrolyte in a redox flow battery with results showing that biologically produced quinones may become a real competitor to the currently available synthetic quinones.
Transcriptional regulation has important roles in various biological processes (e.g., development and metabolism) in filamentous fungi. However, regulatory interactions between transcription factors ...(TFs) and their target genes in these species have only been described in different forms by primary scientific literature, which limits the integrated analysis of these data. Here, we extensively curated the reported transcriptional regulatory interactions in
and
. For each interaction, the identifiers of involved proteins or genes were unified, and the types of supporting experiments were recorded. Then, transcriptional regulatory networks were reconstructed from the interactions supported by classical low-throughput experiments. Analysis of the networks revealed the presence of hub targets regulated by multiple TFs and network motifs of other structures (e.g., regulatory loops). Comparison of the regulatory interactions between the two species identified 33 conserved interactions supported by classical experiments in both species, most of which are involved in the regulation of metabolic genes. We anticipate the curated data would serve as a catalog for the studies of transcriptional regulation in filamentous fungi.
The fungal cell wall protects fungi against threats, both biotic and abiotic, and plays a role in pathogenicity by facilitating host adhesion, among other functions. Although carbohydrates (e.g. ...glucans, chitin) are the most abundant components, the fungal cell wall also harbors ionic proteins, proteins bound by disulfide bridges, alkali-extractable, SDS-extractable, and GPI-anchored proteins, among others; the latter consisting of suitable targets which can be used for fungal pathogen control.
Pseudocercospora fijiensis
is the causal agent of black Sigatoka disease, the principal threat to banana and plantain worldwide. Here, we report the isolation of the cell wall of this pathogen, followed by extensive washing to eliminate all loosely associated proteins and conserve those integrated to its cell wall. In the HF-pyridine protein fraction, one of the most abundant protein bands was recovered from SDS-PAGE gels, electro-eluted and sequenced. Seven proteins were identified from this band, none of which were GPI-anchored proteins. Instead, atypical (moonlight-like) cell wall proteins were identified, suggesting a new class of atypical proteins, bound to the cell wall by unknown linkages. Western blot and histological analyses of the cell wall fractions support that these proteins are true cell wall proteins, most likely involved in fungal pathogenesis/virulence, since they were found conserved in many fungal pathogens.
The correct identification of filamentous fungi is challenging. We evaluated the performance of the VITEK MS v3.0 system (bioMérieux, Marcy-l'Étoile, France) for the identification of a wide spectrum ...of clinically relevant filamentous fungi using a Korean collection. Strains that were added to the upgraded v3.2 database were additionally identified by the VITEK MS v3.2 system. Of the 105 tested isolates, including 37
(nine species), 41 dermatophytes (seven species), and 27 other molds (17 species), 43 (41.0%) showed "no identification" or "multiple species identification" results at the initial VITEK MS testing; these isolates were retested using the same method. Compared with sequence-based identification, the correct identification rate using VITEK MS for
, dermatophytes, other molds, and total mold isolates was 67.6%, 56.1%, 48.1%, and 58.1% at the initial testing and 94.6%, 78.0%, 55.6%, and 78.1% with retesting, respectively. Following retesting, 19 (18.1%) and two (1.9%) isolates showed "no identification" and "misidentification" results, respectively. VITEK MS reliably identified various filamentous fungi recovered in Korea, with a very low rate of misidentification.
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