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Biogenic silver nanoparticles (AgNPs) are considered a promising alternative to their synthetic versions. However, the environmental impact of such nanomaterials is still scarcely understood. Thus, the present study aims at assessing the antimicrobial action and ecotoxicity of AgNPs biosynthesized by the fungus Aspergillus niger IBCLP20 towards three freshwater organisms: Chlorella vulgaris, Daphnia similis, and Danio rerio (zebrafish). AgNPs IBCLP20 showed antibacterial action against Klebsiella pneumoniae between 5 and 100 μg mL

Habitability has been generally defined as the capability of an environment to support life. Ecologists have been using Habitat Suitability Models (HSMs) for more than four decades to study the habitability of Earth from local to global scales. Astrobiologists have been proposing different habitability models for some time, with little integration and consistency among them, being different in function to those used by ecologists. Habitability models are not only used to determine if environments are habitable or not, but they also are used to characterize what key factors are responsible for the gradual transition from low to high habitability states. Here we review and compare some of the different models used by ecologists and astrobiologists and suggest how they could be integrated into new habitability standards. Such standards will help to improve the comparison and characterization of potentially habitable environments, prioritize target selections, and study correlations between habitability and biosignatures. Habitability models are the foundation of planetary habitability science and the synergy between ecologists and astrobiologists is necessary to expand our understanding of the habitability of Earth, the Solar System, and extrasolar planets., Published in Astrobiology, 21(8). arXiv admin note: substantial text overlap with arXiv:2007.05491

Our study evaluated the performance of different two-chambered microbial fuel cell (MFC) prototypes, operated with variable distance between electrodes and Nafion membrane and specific inoculum concentration, applied for vinasse treatment., Instituto de Pesquisa Tecnológica do Estado de São Paulo/Programa Novos Talentos, through individual Research Grant attributed to Cristiane Angélica Ottoni., info:eu-repo/semantics/publishedVersion

The anthraquinone dye Remazol Brilliant Blue R is largely used in the textile industry. However, its removal from wastewaters is costly and complex. Many methods have been tested to solve this ecological problem, but there is still a need for efficient methods. We propose here an alternative use of a two-chambered microbial fuel cell (MFC), fuelled with domestic wastewater in the anodic chamber, to degrade a simulated textile dye effluent made of Remazol Brilliant Blue R inoculated with an immobilised fungal strain, Pleurotus ostreatus URM 4809, as a laccase producer, in the cathodic chamber. The MFC showed continuous synthesis of laccase in the cathodic chamber, which, in turn, promoted the rapid decolourisation, of more than 86\% of the textile dye effluent. The yield was further increased by the addition of glycerol. Electrochemical monitoring also indicated an increase in power density and current density. After 20Â days of MFC operation, 62.1\\% of organic matter was removed in the anodic compartment, thus leaving the effluent with a much lower toxicity., Authors would like to acknowledge the technician and fnancial support of Programa Novos Talentos provided by the Instituto de Pesquisa Tecnológica do Estado de São Paulo (IPT) and Instituto de Estudos Avançados do Mar (IEAMar)., info:eu-repo/semantics/publishedVersion

This study aims to evaluate the effect of freeze-drying and long-term storage on the biotechnological potential of Aspergillus section Nigri strains. Twelve selected strains were freeze-dried and aged by accelerated storage, at 37 °C in the dark, for 2 and 4 weeks. To assess possible changes as a consequence of the ageing in the freeze-drying ampoules, morphological characteristics, mycotoxins and enzymes production, matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALTI-TOF MS) spectra, and M13 phage probe fingerprinting were used as part of a polyphasic approach. Phenotypical changes were observed; nevertheless, they did not substantially affect the potential biotechnological use of these strains. The activity of hydrolytic enzymes (protease, carboxymethylcellulase, xylanase, pectinase and mannanase) was maintained or increased after freeze-drying. MALDI-TOF MS data originated spectra that grouped, for the majority of samples, according to strain independently of preservation time point. M13 profiles revealed the presence of some genetic polymorphisms after preservation. However, the three studied times still clustered for more than 50% of strains. Our results show that the studied strains maintain their biotechnological potential after preservation, with minimal phenotypic alterations. These findings provide evidence that freeze-drying preservation is a suitable option to preserve biotechnologically relevant aspergilli strains from section Nigri, and one should consider that the observed effects might be species/strain-dependent., This research was funded by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020—ProgramaOperacionalRegionaldoNorte. Cl.S.(CledirSantos) thanks the Universidad de La Frontera (Temuco, Chile) for the partial funding from the Project DIUFRO PIA19-0001. R.R. thanks to CONICYT/Chile for the MSc grant Folio N◦ 7317076, Application N◦ 73170764., info:eu-repo/semantics/publishedVersion

The Cabo Verde Islands constitute a biodiversity hotspot, encompassing a wide range of different biotopes. Thus far, most surveys and programmes have focused exclusively on the flora and/or fauna of the islands and no effort has been made to systematically assess and preserve locally existing microbial biodiversity. The absence of such studies is especially troubling regarding their traditional salterns, as many of them have been abandoned, and increase of construction in coastal areas has already started to indelibly change some of these unique ecosystems and will likely obliterate some of them. Here we provide an overview of the preliminary data recently collected from salterns in the islands of Sal, Maio, and Boavista and include details on their previously unreported physical-chemical characteristics (salinity, pH, temperature and ionic composition), as well as first results on microbial metabolic profiling. Our data has shown a wide diversity of environmental niches (particularly noticeable in Maio), and showcased differences in substrate use both between and within different salterns. These are the first step of our ongoing efforts in assisting in the survey of several threatened extreme environments in Cabo Verde, characterising their geochemistry and microbiology, and identifying their potential biotechnological applications.

Copyright © 2015, American Society for Microbiology. All Rights Reserved., Pyrazinamide (PZA) is active against major Mycobacterium tuberculosis species (M. tuberculosis, M. africanum, and M. microti) but not against M. bovis and M. avium. The latter two are mycobacterial species involved in human and cattle tuberculosis and in HIV coinfections, respectively. PZA is a first-line agent for the treatment of human tuberculosis and requires activation by a mycobacterial pyrazinamidase to form the active metabolite pyrazinoic acid (POA). As a result of this mechanism, resistance to PZA, as is often found in tuberculosis patients, is caused by point mutations in pyrazinamidase. In previous work, we have shown that POA esters and amides synthesized in our laboratory were stable in plasma (M. F. Simões, E. Valente, M. J. Gómez, E. Anes, and L. Constantino, Eur J Pharm Sci 37:257-263, 2009, http://dx.doi.org/10.1016/j.ejps.2009.02.012). Although the amides did not present significant activity, the esters were active against sensitive mycobacteria at concentrations 5- to 10-fold lower than those of PZA. Here, we report that these POA derivatives possess antibacterial efficacy in vitro and ex vivo against several species and strains of Mycobacterium with natural or acquired resistance to PZA, including M. bovis and M. avium. Our results indicate that the resistance probably was overcome by cleavage of the prodrugs into POA and a long-chain alcohol. Although it is not possible to rule out that the esters have intrinsic activity per se, we bring evidence here that long-chain fatty alcohols possess a significant antimycobacterial effect against PZA-resistant species and strains and are not mere inactive promoieties. These findings may lead to candidate dual drugs having enhanced activity against both PZA-susceptible and PZA-resistant isolates and being suitable for clinical development., We acknowledge Isabel Portugal (Faculty of Pharmacy, University of Lisbon) for providing the PZA-resistant M. tuberculosis strains. Support from the Portuguese Funding Agency, Fundação para a Ciência e Tecnologia (FCT), projects PTDC/SAU-FCF/101950/2008, PTDC/BIA-BCM/102123/2008, PTDC/SAU-MII/098024/2008, PIC/82859/2007, and PEst-OE/SAU/UI0775/2011, is gratefully acknowledged. D.P., M.F.S., and N.C. are Ph.D. students with FCT fellowships.

Microorganisms produce an enormous variety of chemical compounds. It is of general interest for microbiology and biotechnology researchers to have means to explore information about molecular and genetic basis of functioning of different microorganisms and their ability for bioproduction. To enable such exploration, we compiled 45 topic-specific knowledgebases (KBs) accessible through DESM portal (www.cbrc.kaust.edu.sa/desm). The KBs contain information derived through text-mining of PubMed information and complemented by information data-mined from various other resources (e.g. ChEBI, Entrez Gene, GO, KOBAS, KEGG, UniPathways, BioGrid). All PubMed records were indexed using 4,538,278 concepts from 29 dictionaries, with 1 638 986 records utilized in KBs. Concepts used are normalized whenever possible. Most of the KBs focus on a particular type of microbial activity, such as production of biocatalysts or nutraceuticals. Others are focused on specific categories of microorganisms, e.g. streptomyces or cyanobacteria. KBs are all structured in a uniform manner and have a standardized user interface. Information exploration is enabled through various searches. Users can explore statistically most significant concepts or pairs of concepts, generate hypotheses, create interactive networks of associated concepts and export results. We believe DESM will be a useful complement to the existing resources to benefit microbiology and biotechnology research.

The deep-sea brines of the Red Sea include some of the most extreme and unique environments on Earth. They combine high salinities with increases in temperature, heavy metals, hydrostatic pressure, and anoxic conditions, creating unique settings for thriving populations of novel extremophiles. Despite a recent increase of studies focusing on these unusual biotopes, their viral communities remain unexplored. The current survey explores four metagenomic datasets obtained from different brine–seawater interface samples, focusing specifically on the diversity of their viral communities. Data analysis confirmed that the particle-attached viral communities present in the brine–seawater interfaces were diverse and generally dominated by Caudovirales, yet appearing distinct from sample to sample. With a level of caution, we report the unexpected finding of Phycodnaviridae, which infects algae and plants, and trace amounts of insect-infecting Iridoviridae. Results from Kebrit Deep revealed stratification in the viral communities present in the interface: the upper-interface was enriched with viruses associated with typical marine bacteria, while the lower-interface was enriched with haloviruses and halophages. These results provide first insights into the unexplored viral communities present in deep-sea brines of the Red Sea, representing one of the first steps for ongoing and future sampling efforts and studies.

Covering a quarter of the world’s tropical coastlines and being one of the most threatened ecosystems, mangroves are among the major sources of terrestrial organic matter to oceans and harbor a wide microbial diversity. In order to protect, restore, and better understand these ecosystems, researchers have extensively studied their microbiology, yet few surveys have focused on their fungal communities. Our lack of knowledge is even more pronounced for specific fungal populations, such as the ones associated with the rhizosphere. Likewise, the Red Sea gray mangroves (Avicennia marina) remain poorly characterized, and understanding of their fungal communities still relies on cultivation-dependent methods. In this study, we analyzed metagenomic datasets from gray mangrove rhizosphere and bulk soil samples collected in the Red Sea coast, to obtain a snapshot of their fungal communities. Our data indicated that Ascomycota was the dominant phylum (76%–85%), while Basidiomycota was less abundant (14%–24%), yet present in higher numbers than usually reported for such environments. Fungal communities were more stable within the rhizosphere than within the bulk soil, both at class and genus level. This finding is consistent with the intrinsic patchiness in soil sediments and with the selection of specific microbial communities by plant roots. Our study indicates the presence of several species on this mycobiome that were not previously reported as mangrove-associated. In particular, we detected representatives of several commercially-used fungi, e.g., producers of secreted cellulases and anaerobic producers of cellulosomes. These results represent additional insights into the fungal community of the gray mangroves of the Red Sea, and show that they are significantly richer than previously reported.

In 1990, Woese et al. divided the Tree of Life into three separate domains: Eukarya, Bacteria, and Archaea. Archaea were originally perceived as little more than “odd bacteria” restricted to extreme environmental niches, but later discoveries challenged this assumption. Members of this domain populate a variety of unexpected environments (e.g. soils, seawater, and human bodies), and we currently witness ongoing massive expansions of the archaeal branch of the Tree of Life. Archaea are now recognized as major players in the biosphere and constitute a significant fraction of the earth’s biomass, yet they remain underexplored. An ongoing surge in exploration efforts is leading to an increase in the (a) number of isolated strains, (b) associated knowledge, and (c) utilization of Archaea in biotechnology. They are increasingly employed in fields as diverse as biocatalysis, biocomputing, bioplastic production, bioremediation, bioengineering, food, pharmaceuticals, and nutraceuticals. This chapter provides a general overview on bioprospecting Archaea, with a particular focus on extreme halophiles. We explore aspects such as diversity, ecology, screening techniques and biotechnology. Current and future trends in mining for applications are discussed.

Textile effluents are highly polluting and have variable and complex compositions. They can be extremely complex, with high salt concentrations and alkaline pHs. A fixed-bed bioreactor was used in the present study to simulate a textile effluent treatment, where the white-rot fungus, Trametes versicolor, efficiently decolourised the azo dye Reactive Black 5 over 28 days. This occurred under high alkaline conditions, which is unusual, but advantageous, for successful decolourisation processes. Active dye decolourisation was maintained by operation in continuous culture. Colour was eliminated during the course of operation and maximum laccase (Lcc) activity (80.2 UL1) was detected after glycerol addition to the bioreactor. Lcc2 gene expression was evaluated with different carbon sources and pH values based on reverse transcriptase-PCR (polymerase chain reaction). Glycerol was shown to promote the highest lcc2 expression at pH 5.5, followed by sucrose and then glucose. The highest levels of expression occurred between three and four days, which corroborate the maximum Lcc activity observed for sucrose and glycerol on the bioreactor. These results give new insights into the use of T. versicolor in textile dye wastewater treatment with high pHs., Cledir R. Santos thanks to the Universidad de La Frontera (Temuco, Chile) for the partial funding from both the Project DIUFRO DI16-0135 and the Doctoral Programme in Science of Natural Resources. This study was also supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte.

Microorganisms that inhabit unchartered unique soil such as in the highly saline and hot Red Sea lagoons on the Saudi Arabian coastline, represent untapped sources of potentially new bioactive compounds. In this study, a culture-dependent approach was applied to three types of sediments: mangrove mud (MN), microbial mat (MM), and barren soil (BS), collected from Rabigh harbor lagoon (RHL) and Al-Kharrar lagoon (AKL). The isolated bacteria were evaluated for their potential to produce bioactive compounds. The phylogenetic characterization of 251 bacterial isolates based on the 16S rRNA gene sequencing, supported their assignment to five different phyla: Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, and Planctomycetes. Fifteen putative novel species were identified based on a 16S rRNA gene sequence similarity to other strain sequences in the NCBI database, being ≤98%. We demonstrate that 49 of the 251 isolates exhibit the potential to produce antimicrobial compounds. Additionally, at least one type of biosynthetic gene sequence, responsible for the synthesis of secondary metabolites, was recovered from 25 of the 49 isolates. Moreover, 10 of the isolates had a growth inhibition effect towards Staphylococcus aureus, Salmonella typhimurium and Pseudomonas syringae. We report the previously unknown antimicrobial activity of B. borstelensis, P. dendritiformis and M. salipaludis against all three indicator pathogens. Our study demonstrates the evidence of diverse cultured microbes associated with the Red Sea harbor/lagoon environments and their potential to produce antimicrobial compounds.

Pyrazinamide (PZA) is active against M. tuberculosis and is a first line agent for the treatment of human tuberculosis. PZA is itself a prodrug that requires activation by a pyrazinamidase to form its active metabolite pyrazinoic acid (POA). Since the specificity of cleavage is dependent on a single bacterial enzyme, resistance to PZA is often found in tuberculosis patients. Esters of POA have been proposed in the past as alternatives to PZA however the most promising compounds were rapidly degraded in the presence of serum. In order to obtain compounds that could survive during the transport phase, we synthesized lipophilic ester and amide POA derivatives, studied their activity against M. tuberculosis, their stability in plasma and rat liver homogenate and also their activation by a mycobacterial homogenate. The new lipophilic ester prodrugs were found to be active in concentrations 10-fold lower than those needed for PZA to kill sensitive M. tuberculosis and also have a suitable stability in the presence of plasma. Amides of POA although more stable in plasma have lower activity. The reason can probably be found in the rate of activation of both types of prodrugs; while esters are easily activated by mycobacterial esterases, amides are resistant to activation and are not transformed into POA at a suitable rate.

Mangroves are unique, and endangered, coastal ecosystems that play a vital role in the tropical and subtropical environments. A comprehensive description of the microbial communities in these ecosystems is currently lacking, and additional studies are required to have a complete understanding of the functioning and resilience of mangroves worldwide.In this work, we carried out a metagenomic study by comparing the microbial community of mangrove sediment with the rhizosphere microbiome of Avicennia marina, in northern Red Sea mangroves, along the coast of Saudi Arabia. Our results revealed that rhizosphere samples presented similar profiles at the taxonomic and functional levels and differentiated from the microbiome of bulk soil controls. Overall, samples showed predominance by Proteobacteria, Bacteroidetes and Firmicutes, with high abundance of sulfate reducers and methanogens, although specific groups were selectively enriched in the rhizosphere. Functional analysis showed significant enrichment in ‘metabolism of aromatic compounds’, ‘mobile genetic elements’, ‘potassium metabolism’ and ‘pathways that utilize osmolytes’ in the rhizosphere microbiomes.To our knowledge, this is the first metagenomic study on the microbiome of mangroves in the Red Sea, and the first application of unbiased 454-pyrosequencing to study the rhizosphere microbiome associated with A. marina. Our results provide the first insights into the range of functions and microbial diversity in the rhizosphere and soil sediments of gray mangrove (A. marina) in the Red Sea.

The taxonomy of fungal species, similar to that of many other microorganisms, suffers frequent revisions due to the discovery of new species and to the development and gathering of characterization data and morphological information. Morpho-taxonomy helps in the identification of many species. This work presents the macro, micro-morphological, and spectral mass analyses for phenotypic characterization of 13 species of Aspergillus section Nigri, showing that the characterization of spores (conidia) by scanning electron microscopy can be used as a tool to discriminate key morphological characteristics and separate closely related fungi. These results were corroborated by colony plates, stereomicroscopy, light microscopy, and spectral mass data., This research has received funding from the European Community's Seventh Framework Programme (FP7, 2007-2013), Research Infrastructures action, under grant No. FP7-228310 (EMbaRC project). M.F. Simoes acknowledges FCT-Portugal for the scholarship SFRH/BD/64260/2009.

Fungi are a diverse group of unique eukaryotic organisms currently accepted as the Eumycota kingdom. The (under) estimated number of fungal species is 1.5 × 106 of which only a small number have been identified (ca. 8–10%). They are ubiquitous in nature with an extraordinary ability to decompose plant wastes while also causing much spoilage of food and other relevant commodities. Certain species are used directly as food and others in the manufacture of foodstuffs, antibiotics, enzymes, organic acids and alcohol. Still others can infect humans, animals and crops. Information about each microorganism (e.g. morphological and molecular descriptions, including modern spectral data – MALDI-TOF MS, physiological and biochemical features, ecological roles, and societal risks or benefits) is the key element in fungal identification. In order to attain a sound fungal identification a polyphasic approach is required. It is achieved through the integration of all biological traits data. Fungal service culture collections have well established management systems and preservation techniques that are of elemental importance and guarantee the proper identification and characterisation of environmental fungal isolates. They also assure the continuity of taxonomic and comparative studies and fungal availability for biotechnological exploitation. To foster bio-economy and sustain the biotechnological developments new demands for quality control of fungal holdings preserved in culture collections are in course. The quality control system is associated with new guidelines for the culture collections to operate at global level and to adapt the traditional fungal repositories into the new OECD concept of Biological Resource Centres (BRCs)., (undefined)

Fungi, also well known as moulds, yeasts and mushrooms, are a diverse group of eukaryotic organisms which belonging to the "fifth kingdom". TheyFungi are ubiquitous in nature with microorganisms and display an extraordinary ability to decompose wastes while also causing much spoilage of food. Fungi have a high nuisance value as contaminants in laboratories and industrial settings. diversity with primary role in the nature as decomposers. Certain species are used directly as food and others in the manufacture of foodstuffs, antibiotics, enzymes, organic acids and alcohol. Still others can infect humans. Different classes of cChemicals have antifungal activity which turns them potentials biocidesmicrobicides. BiocidesMicrobicides can besuch as acids, alkalis, alcohols, aldehydes and halogens compounds. hHeavy metals have also shown antifungal activity as well peroxides compounds, phenolicss and surfactants show fungicidal activity; Different combinations and concentrations or formulations of thesesuch chemicals have been used forduring decades as microbicides against a variety of fungi. with success as disinfectants. This chapter addresses the most recent developments in this field on antifungal activity of biocidesmicrobicides. © 2013 Blackwell Publishing Ltd., (undefined)

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article i nfo Article history: One of the main problems in combating tuberculosis is caused by a poor penetration of drugs into the mycobacterial cells. A prodrug approach via activation inside mycobacterial cells is a possible strategy to overcome this hurdle and achieve efficient drug uptake. Esters are attractive candidates for such a strategy and we and others communicated previously the activity of esters of weak organic acids against mycobacteria. However very little is known about ester hydrolysis by mycobacteria and no biological model is available to study the activation of prodrugs by these microorganisms. To begin filling this gap, we have embarked in a project to develop an in vitro method to study prodrug activation by mycobacteria using Mycobacterium smegmatis homogenates. Model ester substrates were ethyl nicotinate and ethyl benzoate whose hydrolysis was monitored and characterized kinetically. Our studies showed that in M. smegmatis most esterase activity is associated with the soluble fraction (cytosol) and is preserved by storage at 5 °C or at room temperature for one hour, or by storage at �80 °C up to one year. In the range of homogenate concentrations studied (5-80% in buffer), kobs varied linearly with homogenate concentration for both substrates. We also found that the homogenates showed Michaelis-Menten kinetics behavior with both prodrugs. Since ethyl benzoate is a good substrate for the mycobacterial esterases, this compound can be used to standardize the esterasic activity of homogenates, allowing results of incubations of prodrugs with homogenates from different batches to be readily compared.

Pyrazinamide (PZA) is active against M. tuberculosis and is a first line agent for the treatment of human tuberculosis. PZA is itself a prodrug that requires activation by a pyrazinamidase to form its active metabolite pyrazinoic acid (POA). Since the specificity of cleavage is dependent on a single bacterial enzyme, resistance to PZA is often found in tuberculosis patients. Esters of POA have been proposed in the past as alternatives to PZA however the most promising compounds were rapidly degraded in the presence of serum. In order to obtain compounds that could survive during the transport phase, we synthesized lipophilic ester and amide POA derivatives, studied their activity against M. tuberculosis, their stability in plasma and rat liver homogenate and also their activation by a mycobacterial homogenate. The new lipophilic ester prodrugs were found to be active in concentrations 10-fold lower than those needed for PZA to kill sensitive M. tuberculosis and also have a suitable stability in the presence of plasma. Amides of POA although more stable in plasma have lower activity. The reason can probably be found in the rate of activation of both types of prodrugs; while esters are easily activated by mycobacterial esterases, amides are resistant to activation and are not transformed into POA at a suitable rate.

Species of Aspergillus from section Nigri, also known as black aspergilli, are distributed worldwide and have been widely used for purposes of various types such as: biotechnological, industrial, medical, among others. They have been extensively studied for being the causing agents of biodeterioration of commodities and food.Within this section, new species have been recently described and among them Aspergillus ibericus and Aspergillus uvarum were both isolated from grapes. The polyphasic approach used in the analysis of these species, either by morphological techniques as well as by molecular methods, allowed not only their characterisation but also their consequent separation from all others in the section. Microbial taxonomy has the identification of species as one of its fundamental goals. Data such as: morphological characteristics description, physiological and biochemical properties, ecological roles, and societal risks or benefits, are key elements in any fungal identification process. But, this process is subjected to periodic changes due to frequent revisions of the taxonomic schemes, therefore becoming time consuming and more demanding and difficult, even for skilled specialists. Furthermore, each taxonomic group has specialised literature, terminology and characters. This takes place since identifications have difficulties of consensual naming, depending on the criteria used and the amount of information available when producing all data. It is increasingly becoming clear that, to better achieve a more accurate concept of species, microbial identification and authentication require a polyphasic approach to produce consistent, useful and quality data.Characterisation of morphologic and structural aspects of spores from Aspergillus strains, section Nigri, has been carried out using scanning electron microscopy (SEM) and intends to contribute to the associated data of the strains from this section.Colonies from 13 Aspergillus from section Nigri, from the Micoteca da Universidade do Minho (MUM), were grown at 25 ºC for 3 or 4 days in malt extract agar directly mounted in a sterilised SEM stub. The samples were covered with a mixture of gold and platinum (80/20%) and then examined in the SEM [NanoSEM - FEI NovaTM 200 (FEG/SEM); EDAX - Pegasus X4M (EDS/EBSD)]. A stereomicroscope (Leica MZ12.5) was used to have a clear image comparison of the size of the conidial head.Although the analysed strains presented dimensional, morphological and structural diversity, common or typical features could be inferred and related to each taxon like those represented in Fig 1.From the SEM analysis we were able to conclude that in the section Nigri of genus Aspergillus the spore wall ornamentation, and its size and shape continue to present themselves as important primary diagnostic traits for species differentiation.

Mycobacterium tuberculosis complex are among the most successful pathogens. Their success resides in the ability to interfere with intracellular traffic avoiding natural pathways of the phagosome maturation. Recently, mycobacteria escape from the phagosome to the cytosol was investigated as an alternative survival strategy. In this context we decided to determine the exact intracellular location of Mycobacterium bovis in different host macrophages and characterize the pathogen intracellular niche for survival. The main goal here was to characterize live vs dead M. bovis spp phagosome in different host macrophages. Macrophages infection, fluorescence and EM procedures were carried out as described previously.

Made available in DSpace on 2018-12-11T16:45:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-12-01 The present work had the goal of screening a batch of 20 fungal strains, isolated from sugar cane plantation soil, in order to identify those capable of biosynthesis of silver nanoparticles. These nanoparticles are known to have a large and effective application in clinical microbiology. Four strains were found to be capable of biosynthesis of silver nanoparticles. The biosynthesised nanoparticles were characterised by UV–vis spectroscopy, scanning electron microscopy, EDX, and XRD. They were found to have an average size of 30–100 nm, a regular round shape, and potential antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The antimicrobial activity was found to be directly related to the nanoparticles concentration. Mycogenic synthesis of nanoparticles is a green biogenic process preferable to other alternatives. Because fungi are great producers of extracellular enzymes this process makes scaling-up an easier task with high importance for clinical microbiology on the fight against microbial resistance, as well as for other industrial applications. Biosciences Institute São Paulo State University-UNESP, Praça Infante Dom Henrique s/no Biology Department Edge Hill University, St Helens Road, Lancashire Richmond Pharmacology Ltd St George’s University London Laboratório de Biotecnologia Industrial Instituto de Pesquisa Tecnológica do Estado de São Paulo Departamento de Química Universidade Federal do Amazonas, Av. General Rodrigo Octávio, Coroado I, 6200 Biosciences Institute São Paulo State University-UNESP, Praça Infante Dom Henrique s/no