58 results on '"Esteves AC"'
Search Results
2. PIN32 - Benefícios Materiais Como Incentivo Para Redução de Abandono de Tratamento de Tuberculose em Pessoas Vivendo em Situação de Rua: Revisão de Análises Econômicas
- Author
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Elias, FT, Rodrigues, D, Esteves, AC, and Silva, E
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- 2015
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3. The "target sign": A hallmark of lupus enteritis.
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Esteves AC, Mendes B, Assunção H, and Inês L
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- 2024
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4. The 'Erlenmeter': a low-cost, open-source turbidimeter for no-sampling phenotyping of microorganism growth.
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Serôdio J, Bastos A, Frankenbach S, Frommlet JC, Esteves AC, and Queiroga H
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- Microalgae growth & development, Phenotype, Escherichia coli growth & development, Escherichia coli isolation & purification, Saccharomyces cerevisiae growth & development, Nephelometry and Turbidimetry instrumentation, Nephelometry and Turbidimetry methods
- Abstract
This work presents a low-cost, open-source turbidimeter, the 'Erlenmeter', designed to monitor the growth of microorganisms in batch cultures. It is easy to build, based exclusively on inexpensive off-the-shelf electronic components and 3D-printed parts. The Erlenmeter allows measuring the optical density of cultures on standard Erlenmeyer flasks without the need to open the flasks to collect aliquots, ensuring speed, minimal use of consumables, and elimination of the risk of contamination. These features make it particularly well-suited not just for routine research assays but also for experimental teaching. Here we illustrate the use of the Erlenmeter turbidimeter to record the growth of the microalga Phaeodactylum tricornutum , of the bacterium Escherichia coli , and of the yeast Saccharomyces cerevisiae , model organisms that are widely used in research and teaching. The Erlenmeter allows a detailed characterization of the growth curves of all organisms, confirming its usefulness for studying microbial populations dynamics both for research purposes and in classroom settings., Competing Interests: The authors declare there are no competing interests., (©2024 Serôdio et al.)
- Published
- 2024
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5. How temperature modulates the expression of pathogenesis-related molecules of the cross-kingdom pathogen Lasiodiplodia hormozganensis.
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Félix C, Meneses R, Gonçalves MFM, Duarte AS, Jorrín-Novo JV, van de Peer Y, Deforce D, Van Nieuwerburgh F, Alves A, and Esteves AC
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- Plant Diseases microbiology, Fungal Proteins metabolism, Fungal Proteins genetics, Transcriptome, Ascomycota physiology, Ascomycota genetics, Temperature
- Abstract
Lasiodiplodia hormozganensis, initially recognized as a fungal plant pathogen, is recognized now acknowledged as a potential threat to humans. However, our understanding of the pathogenesis mechanisms of Lasiodiplodia species remains limited, and the impact of temperature on its pathogenicity is unclear. This study aims to elucidate the effects of temperature on the biology of L. hormozganensis, focusing on the expression of pathogenesis-related molecules and its ability to function as a cross-kingdom pathogen. We conducted experiments at two different temperatures, 25 and 37 °C, analyzing the proteome and transcriptome of L. hormozganensis. Using strain CBS339.90, initially identified as L. theobromae but confirmed through ITS and tef1-α sequence analysis to be L. hormozganensis, we aimed to understand the fungus's protein expression under varying temperature conditions. Results from the functional analysis of the secretome at 25 °C showed a noteworthy presence of proteins related to carbohydrate metabolism, catabolism, plant cell wall degradation, and pathogenesis. However, when grown at 37 °C, the fungus exhibited an increased production of stress response and pathogenesis-related proteins. Our findings identified various pathways crucial for pathogenesis in both plants and humans, suggesting that L. hormozganensis possesses the genetic foundation to infect both hosts. Specific pathogenesis-related proteins, including the phytotoxin snodprot1, aspartic protease aspergillopepsin, and virulence protein SSD1, were also identified. Concluding, we propose a possible mechanism of how L. hormozganensis adapts to different temperatures. The shift in temperature results in the expression of genes that favor human related pathogenesis molecules., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
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- 2024
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6. Combination treatment with rituximab and belimumab in shrinking lung syndrome in systemic lupus erythematosus.
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Esteves AC, Mendes B, Assunção H, and Inês LS
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- Humans, Rituximab adverse effects, Lung, Autoimmune Diseases, Lupus Erythematosus, Systemic complications, Lupus Erythematosus, Systemic diagnosis, Lupus Erythematosus, Systemic drug therapy, Muscular Diseases, Antibodies, Monoclonal, Humanized
- Published
- 2024
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7. Special Issue: "Fungi: What Have We Learned from Omics?"
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Esteves AC
- Abstract
Fungi are vast in terms of diversity, ecological roles, habitats they occupy, physiology, metabolism, and in many other characteristics [...].
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- 2022
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8. COVID-19 Salivary Protein Profile: Unravelling Molecular Aspects of SARS-CoV-2 Infection.
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Esteves E, Mendes VM, Manadas B, Lopes R, Bernardino L, Correia MJ, Barros M, Esteves AC, and Rosa N
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COVID-19 is the most impacting global pandemic of all time, with over 600 million infected and 6.5 million deaths worldwide, in addition to an unprecedented economic impact. Despite the many advances in scientific knowledge about the disease, much remains to be clarified about the molecular alterations induced by SARS-CoV-2 infection. In this work, we present a hybrid proteomics and in silico interactomics strategy to establish a COVID-19 salivary protein profile. Data are available via ProteomeXchange with identifier PXD036571. The differential proteome was narrowed down by the Partial Least-Squares Discriminant Analysis and enrichment analysis was performed with FunRich. In parallel, OralInt was used to determine interspecies Protein-Protein Interactions between humans and SARS-CoV-2. Five dysregulated biological processes were identified in the COVID-19 proteome profile: Apoptosis, Energy Pathways, Immune Response, Protein Metabolism and Transport. We identified 10 proteins (KLK 11, IMPA2, ANXA7, PLP2, IGLV2-11, IGHV3-43D, IGKV2-24, TMEM165, VSIG10 and PHB2) that had never been associated with SARS-CoV-2 infection, representing new evidence of the impact of COVID-19. Interactomics analysis showed viral influence on the host immune response, mainly through interaction with the degranulation of neutrophils. The virus alters the host's energy metabolism and interferes with apoptosis mechanisms.
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- 2022
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9. Unveiling the Secretome of the Fungal Plant Pathogen Neofusicoccum parvum Induced by In Vitro Host Mimicry.
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Nazar Pour F, Pedrosa B, Oliveira M, Fidalgo C, Devreese B, Driessche GV, Félix C, Rosa N, Alves A, Duarte AS, and Esteves AC
- Abstract
Neofusicoccum parvum is a fungal plant pathogen of a wide range of hosts but knowledge about the virulence factors of N. parvum and host-pathogen interactions is rather limited. The molecules involved in the interaction between N. parvum and Eucalyptus are mostly unknown, so we used a multi-omics approach to understand pathogen-host interactions. We present the first comprehensive characterization of the in vitro secretome of N. parvum and a prediction of protein-protein interactions using a dry-lab non-targeted interactomics strategy. We used LC-MS to identify N. parvum protein profiles, resulting in the identification of over 400 proteins, from which 117 had a different abundance in the presence of the Eucalyptus stem. Most of the more abundant proteins under host mimicry are involved in plant cell wall degradation (targeting pectin and hemicellulose) consistent with pathogen growth on a plant host. Other proteins identified are involved in adhesion to host tissues, penetration, pathogenesis, or reactive oxygen species generation, involving ribonuclease/ribotoxin domains, putative ricin B lectins, and necrosis elicitors. The overexpression of chitosan synthesis proteins during interaction with the Eucalyptus stem reinforces the hypothesis of an infection strategy involving pathogen masking to avoid host defenses. Neofusicoccum parvum has the molecular apparatus to colonize the host but also actively feed on its living cells and induce necrosis suggesting that this species has a hemibiotrophic lifestyle.
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- 2022
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10. Why is Palliative Care Training During the Portuguese Family Medicine Residency Program Not Mandatory?
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Castro RF, Esteves AC, Gouveia M, and Reis-Pina P
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- Curriculum, Family Practice education, Humans, Palliative Care, Portugal, Surveys and Questionnaires, Internship and Residency
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- 2022
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11. Population wide testing pooling strategy for SARS-CoV-2 detection using saliva.
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Esteves E, Mendes AK, Barros M, Figueiredo C, Andrade J, Capelo J, Novais A, Rebelo C, Soares R, Nunes A, Ferreira A, Lemos J, Duarte AS, Silva RM, Inácio Bernardino L, Correia MJ, Esteves AC, and Rosa N
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- COVID-19 diagnosis, Humans, Reproducibility of Results, Sensitivity and Specificity, COVID-19 Testing methods, SARS-CoV-2 isolation & purification, Saliva virology, Specimen Handling methods
- Abstract
SARS-CoV-2 pandemic has forced frequent testing of populations. It is necessary to identify the most cost-effective strategies for the detection of COVID-19 outbreaks. Nasopharyngeal samples have been used for SARS-CoV-2 detection but require a healthcare professional to collect the sample and cause discomfort and pain to the individual. Saliva has been suggested as an appropriate fluid for the diagnosis of COVID-19. We have investigated the possibility of using pools of saliva samples to detect SARS-CoV-2 in symptomatic and asymptomatic patients. Two hundred and seventy-nine saliva samples were analyzed through RT-PCR of Envelope, Nucleocapsid and Open Reading Frame 1ab genes. Reproducibility assays showed an almost perfect agreement as well as high sensitivity (96.6%), specificity (96.8%), positive predicted value (96.6%), and negative predicted value (96.8%). The average Cycle Threshold of the genes detected was 29.7. No significant differences (p > 0.05) were detected when comparing the cycle threshold average of two consecutive reactions on the same positive saliva samples. Saliva samples have a higher median viral load (32.6) than in nasopharyngeal samples (28.9), although no significant differences were detected (p > 0.05). Saliva-pool samples allowed effective SARS-CoV-2 screening, with a higher sensibility (96.9%) on 10-sample pools than in 20-sample pools (87.5%). Regardless of pools size specificity was high (99.9%) and an almost perfect agreement was observed. Our strategy was successfully applied in population wide testing of more than 2000 individuals, showing that it is possible to use pooled saliva as diagnostic fluid for SARS-CoV-2 infection., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2022
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12. Genomic and Metabolomic Analyses of the Marine Fungus Emericellopsis cladophorae : Insights into Saltwater Adaptability Mechanisms and Its Biosynthetic Potential.
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Gonçalves MFM, Hilário S, Van de Peer Y, Esteves AC, and Alves A
- Abstract
The genus Emericellopsis is found in terrestrial, but mainly in marine, environments with a worldwide distribution. Although Emericellopsis has been recognized as an important source of bioactive compounds, the range of metabolites expressed by the species of this genus, as well as the genes involved in their production are still poorly known. Untargeted metabolomics, using UPLC- QToF-MS/MS, and genome sequencing (Illumina HiSeq) was performed to unlock E . cladophorae MUM 19.33 chemical diversity. The genome of E . cladophorae is 26.9 Mb and encodes 8572 genes. A large set of genes encoding carbohydrate-active enzymes (CAZymes), secreted proteins, transporters, and secondary metabolite biosynthetic gene clusters were identified. Our analysis also revealed genomic signatures that may reflect a certain fungal adaptability to the marine environment, such as genes encoding for (1) the high-osmolarity glycerol pathway; (2) osmolytes' biosynthetic processes; (3) ion transport systems, and (4) CAZymes classes allowing the utilization of marine polysaccharides. The fungal crude extract library constructed revealed a promising source of antifungal (e.g., 9,12,13-Trihydroxyoctadec-10-enoic acid, hymeglusin), antibacterial (e.g., NovobiocinA), anticancer (e.g., daunomycinone, isoreserpin, flavopiridol), and anti-inflammatory (e.g., 2'-O-Galloylhyperin) metabolites. We also detected unknown compounds with no structural match in the databases used. The metabolites' profiles of E . cladophorae MUM 19.33 fermentations were salt dependent. The results of this study contribute to unravel aspects of the biology and ecology of this marine fungus. The genome and metabolome data are relevant for future biotechnological exploitation of the species.
- Published
- 2021
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13. Genome and Metabolome MS-Based Mining of a Marine Strain of Aspergillus affinis .
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Gonçalves MFM, Hilário S, Tacão M, Van de Peer Y, Alves A, and Esteves AC
- Abstract
Aspergillus section Circumdati encompasses several species that express both beneficial (e.g., biochemical transformation of steroids and alkaloids, enzymes and metabolites) and harmful compounds (e.g., production of ochratoxin A (OTA)). Given their relevance, it is important to analyze the genetic and metabolic diversity of the species of this section. We sequenced the genome of Aspergillus affinis CMG 70, isolated from sea water, and compared it with the genomes of species from section Circumdati , including A. affinis 's strain type. The A. affinis genome was characterized considering secondary metabolites biosynthetic gene clusters (BGCs), carbohydrate-active enzymes (CAZymes), and transporters. To uncover the biosynthetic potential of A. affinis CMG 70, an untargeted metabolomics (LC-MS/MS) approach was used. Cultivating the fungus in the presence and absence of sea salt showed that A. affinis CMG 70 metabolite profiles are salt dependent. Analyses of the methanolic crude extract revealed the presence of both unknown and well-known Aspergillus compounds, such as ochratoxin A, anti-viral (e.g., 3,5-Di-tert-butyl-4-hydroxybenzoic acid and epigallocatechin), anti-bacterial (e.g., 3-Hydroxybenzyl alcohol, l-pyroglutamic acid, lecanoric acid), antifungal (e.g., lpyroglutamic acid, 9,12,13-Trihydroxyoctadec-10-enoic acid, hydroxyferulic acid), and chemotherapeutic (e.g., daunomycinone, mitoxantrone) related metabolites. Comparative analysis of 17 genomes from 16 Aspergillus species revealed abundant CAZymes (568 per species), secondary metabolite BGCs (73 per species), and transporters (1359 per species). Some BGCs are highly conserved in this section (e.g., pyranonigrin E and UNII-YC2Q1O94PT (ACR toxin I)), while others are incomplete or completely lost among species (e.g., bikaverin and chaetoglobosins were found exclusively in series Sclerotiorum , while asperlactone seemed completely lost). The results of this study, including genome analysis and metabolome characterization, emphasize the molecular diversity of A. affinis CMG 70, as well as of other species in the section Circumdati .
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- 2021
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14. Photodynamic inactivation of Lasiodiplodia theobromae : lighting the way towards an environmentally friendly phytosanitary treatment.
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Garcia M, David B, Sierra-Garcia IN, Faustino MAF, Alves A, Esteves AC, and Cunha A
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- Ascomycota, Cations, Photosensitizing Agents pharmacology, Sunlight, Porphyrins
- Abstract
The fungus Lasiodiplodia theobromae is one of the main causal agents of trunk canker and dieback of grapevine. The objective of this work was to evaluate the efficiency of photodynamic inactivation (PDI) of L. theobromae with synthetic and natural photosensitizers and irradiation with either sunlight or artificial photosynthetically active radiation. Although the growth of the mycelium could not be completely prevented with natural sunlight irradiation, phenothiazine dyes (methylene blue, MB; toluidine blue O, TBO), riboflavin and a cationic porphyrin (Tetra-Py
+ -Me) caused complete inhibition under continuous irradiation with artificial light. Free radicals were the main cytotoxic agents in the PDI with MB, indicating the predominance of the type I mechanism. PDI with MB or Tetra-Py+ -Me may represent a promising approach for the sanitation of vine material in greenhouse nurseries, in order to reduce the risk of infection upon grafting.- Published
- 2021
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15. Peptone from casein, an antagonist of nonribosomal peptide synthesis: a case study of pedopeptins produced by Pedobacter lusitanus NL19.
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Covas C, Almeida B, Esteves AC, Lourenço J, Domingues P, Caetano T, and Mendo S
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- Molecular Structure, Pedobacter metabolism, Peptides, Cyclic biosynthesis, Peptides, Cyclic chemistry, Peptones chemistry, Caseins chemistry, Pedobacter chemistry, Peptides, Cyclic antagonists & inhibitors, Peptones metabolism
- Abstract
Novel natural products are urgently needed to address the worldwide incidence of bacterial resistance to antibiotics. Extreme environments are a major source of novel compounds with unusual chemical structures. Pedobacter lusitanus NL19 is a new bacterial species that was isolated from one such environment and which produces compounds with potent activity against relevant microorganisms in the clinical, food, veterinary and aquaculture areas. The production of antimicrobials by P. lusitanus NL19 was identified in tryptic soy agar (TSA), but not in its equivalent broth (TSB). It was observed that in TSB medium a high concentration of casein peptone (PC) repressed the production of antibacterial compounds. HPLC, MS and MS/MS spectra with de novo sequencing revealed that the bioactivity of P. lusitanus NL19 was due to the production of pedopeptins. Hence, biosynthesis of pedopeptins is inhibited by high concentrations of PC in the broth medium. Furthermore, a nonribosomal peptide synthetase (NRPS) gene cluster was identified in the genome of NL19 encoding the biosynthesis of the peptides. qPCR analysis confirmed that the transcription of these genes is repressed in cells cultivated in high concentrations of PC. It is shown that pedopeptins are nonribosomal peptides with a broad-spectrum activity, including against Gram-positive and Gram-negative bacteria and yeasts., (Copyright © 2020. Published by Elsevier B.V.)
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- 2021
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16. Revealing the hidden diversity of marine fungi in Portugal with the description of two novel species, Neoascochyta fuci sp. nov. and Paraconiothyrium salinum sp. nov.
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Gonçalves MFM, Esteves AC, and Alves A
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- Ascomycota isolation & purification, DNA, Fungal genetics, Ecosystem, Mycological Typing Techniques, Portugal, Sequence Analysis, DNA, Ascomycota classification, Phylogeny, Seawater microbiology
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Fungi are ubiquitous organisms with a wide distribution in almost all ecosystems, including marine environments. Coastal and estuarine ecosystems remain poorly unexplored as fungal habitats, potentially harbouring a hidden diversity with important ecological roles. During an extensive survey of marine fungi in coastal and estuarine Portuguese environments, a collection of 612 isolates was obtained from water, algae, sponges and driftwood. From these, 282 representative isolates were selected through microsatellite-primed PCR (MSP-PCR) fingerprinting analysis, which were identified based on DNA sequence data. The collection yielded 117 taxa from 38 distinct genera, which were identified using DNA sequence analysis. Overall, fungal community composition varied with host/substrate, but the most abundant taxa in the collection were Cladosporium cladosporioides , Penicillium terrigenum , Penicillium brevicompactum and Fusarium equiseti / incarnatum complex. The occurrence of a high fungal diversity harbouring novel species was disclosed. Through a multilocus phylogeny based on ITS, tub2 and tef1-α sequences, in conjunction with morphological and physiological data, we propose Neoascochyta fuci sp. nov. and Paraconiothyrium salinum sp. nov.
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- 2020
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17. Effect of γ-Aminobutyric Acid (GABA) on the Metabolome of Two Strains of Lasiodiplodia theobromae Isolated from Grapevine.
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Salvatore MM, Félix C, Lima F, Ferreira V, Duarte AS, Salvatore F, Alves A, Esteves AC, and Andolfi A
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- Ascomycota isolation & purification, Species Specificity, Ascomycota metabolism, Metabolome drug effects, Vitis microbiology, gamma-Aminobutyric Acid pharmacology
- Abstract
The effect of γ-aminobutyric acid (GABA) on the metabolome of two strains of Lasiodiplodia theobromae isolated from grapevine that hold a different degree of virulence to the host plant (LA-SOL3 (more virulent), LA-SV1 (less virulent)) was investigated. The culture filtrates and crude extracts from the two strains grown in the presence and absence of 10 mM of GABA were tested for phytotoxicity on tomato plant cuttings and leaves, respectively. Considering the opportunistic nature of this fungus for humans, crude extracts were also tested for cytotoxicity on mammalian cell lines. We found that culture filtrates and crude extracts have a decreased toxicity in the presence of GABA. Metabolomic analysis, conducted on both strains at both growth conditions, revealed the production of several compounds, such as indole-3-carboxylic acid (ICA, which is the main compound produced by L. theobromae ), 3-indolecarboxyaldehyde, (3 R ,4 S )-botryodiplodin, ( R )-mellein. Finally, data demonstrate that GABA both induces a decrease in the amount of ICA, and a diversification of the metabolites produced by L. theobromae .
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- 2020
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18. Effect of temperature on the phytotoxicity and cytotoxicity of Botryosphaeriaceae fungi.
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Nazar Pour F, Ferreira V, Félix C, Serôdio J, Alves A, Duarte AS, and Esteves AC
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- 3T3 Cells, Animals, Ascomycota physiology, Chlorocebus aethiops, Mice, Plant Leaves microbiology, Temperature, Vero Cells, Ascomycota pathogenicity, Cell Survival, Solanum lycopersicum microbiology, Plant Diseases microbiology
- Abstract
Botryosphaeriaceae fungi are phytopathogens and human opportunists. The influence of temperature on the phytotoxicity and cytotoxicity of culture filtrates of five Botryosphaeriaceae species was investigated. All culture filtrates of fungi grown at 25 °C were phytotoxic: symptoms were evaluated based on visual inspection of necrosis areas and on the maximum quantum yield of photosystem II, F
v /Fm . Diplodiacorticola and Neofusicoccum kwambonambiense were the most phytotoxic, followed by Neofusicoccum parvum CAA704 and Botryosphaeria dothidea. Phytotoxicity dramatically decreased when strains were grown at 37 °C, except for B. dothidea. All strains, except N. parvum CAA366 and Neofusicoccum eucalyptorum, grown either at 25 °C or 37 °C, were toxic to mammalian cells; at 25 °C and at 37°C, D. corticola and B. dothidea were the most cytotoxic, respectively. Although the toxicity of B. dothidea to both cell lines and of N. kwambonambiense to Vero cells increased with temperature, the opposite was found for the other species tested. Our results suggest that temperature modulates the expression of toxic compounds that, in a scenario of a global increase of temperature, may contribute to new plant infections but also human infections, especially in the case of B. dothidea., (Copyright © 2020 British Mycological Society. Published by Elsevier Ltd. All rights reserved.)- Published
- 2020
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19. Toxicity of Recombinant Necrosis and Ethylene-Inducing Proteins (NLPs) from Neofusicoccum parvum .
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Nazar Pour F, Cobos R, Rubio Coque JJ, Serôdio J, Alves A, Félix C, Ferreira V, Esteves AC, and Duarte AS
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- Animals, Ascomycota genetics, Ascomycota metabolism, Cell Survival drug effects, Chlorocebus aethiops, Chlorophyll metabolism, Cloning, Molecular, Fungal Proteins genetics, Fungal Proteins metabolism, Solanum lycopersicum metabolism, Necrosis, Plant Leaves metabolism, Recombinant Proteins toxicity, Vero Cells, Fungal Proteins toxicity, Solanum lycopersicum drug effects, Plant Leaves drug effects
- Abstract
Neofusicoccum parvum is a fungal pathogen associated with a wide range of plant hosts. Despite being widely studied, the molecular mechanism of infection of N. parvum is still far from being understood. Analysis of N. parvum genome lead to the identification of six putative genes encoding necrosis and ethylene-inducing proteins (NLPs). The sequence of NLPs genes (NprvNep 1-6) were analyzed and four of the six NLP genes were successfully cloned, expressed in E. coli and purified by affinity chromatography. Pure recombinant proteins were characterized according to their phytotoxic and cytotoxic effects to tomato leaves and to mammalian Vero cells, respectively. These assays revealed that all NprvNeps tested are cytotoxic to Vero cells and also induce cell death in tomato leaves. NprvNep2 was the most toxic to Vero cells, followed by NprvNep1 and 3. NprvNep4 induced weaker, but, nevertheless, still significant toxic effects to Vero cells. A similar trend of toxicity was observed in tomato leaves: the most toxic was NprvNep 2 and the least toxic NprvNep 4. This study describes for the first time an overview of the NLP gene family of N. parvum and provides additional insights into its pathogenicity mechanism.
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- 2020
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20. Novel halotolerant species of Emericellopsis and Parasarocladium associated with macroalgae in an estuarine environment.
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Gonçalves MFM, Vicente TFL, Esteves AC, and Alves A
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- Animals, DNA, Fungal genetics, DNA, Ribosomal Spacer genetics, Genes, Fungal genetics, Hypocreales cytology, Hypocreales genetics, Hypocreales growth & development, Phylogeny, Porifera microbiology, Portugal, Seawater microbiology, Sequence Analysis, DNA, Estuaries, Hypocreales classification, Seaweed microbiology
- Abstract
Macroalgae of the genera Fucus, Ulva , and Enteromorpha are typically abundant in estuaries. Endophytic fungi may have beneficial effects on the hosts affecting their ability to cope with stress. They are also a source of biologically active compounds. However, little is known about the endophytic fungi that colonize these macroalgae. Endophytic isolates were obtained from macroalgae from various sites in the estuary Ria de Aveiro (Portugal), as well as from saline water and sponges. Six Acremonium -like species could not be affiliated to any known species. Phylogenetic analyses based on internal transcribed spacer (ITS) region of the ribosomal DNA and β-tubulin ( tub2 ) and actin ( act1 ) genes placed these species in the genera Emericellopsis and Parasarocladium , but distinct from all currently known species. Although sharing morphological characteristics with the most closely related species, these genera differ in micromorphological and molecular characters. Thus, three novel species of Emericellopsis ( E. cladophorae , sp. nov., E. enteromorphae , sp. nov., and E. phycophila , sp. nov.) and three novel species of Parasarocladium ( P. aestuarinum , sp. nov., P. alavariense , sp. nov., and P. fusiforme , sp. nov.) are proposed.
- Published
- 2020
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21. Tracking the functional meaning of the human oral-microbiome protein-protein interactions.
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Rosa N, Campos B, Esteves AC, Duarte AS, Correia MJ, Silva RM, and Barros M
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- Bacterial Proteins immunology, Biomarkers metabolism, Dental Caries genetics, Dental Caries immunology, Dental Caries metabolism, Fungal Proteins immunology, Gingivitis genetics, Gingivitis immunology, Gingivitis metabolism, Host-Pathogen Interactions, Humans, Microbiota immunology, Mouth immunology, Mouth metabolism, Mouth Neoplasms genetics, Mouth Neoplasms immunology, Mouth Neoplasms metabolism, Mouth Neoplasms microbiology, Peri-Implantitis genetics, Peri-Implantitis immunology, Peri-Implantitis metabolism, Peri-Implantitis microbiology, Periodontitis genetics, Periodontitis immunology, Periodontitis metabolism, Precancerous Conditions genetics, Precancerous Conditions immunology, Precancerous Conditions metabolism, Precancerous Conditions microbiology, Protein Interaction Mapping, Proteomics methods, Salivary Proteins and Peptides immunology, Bacterial Proteins metabolism, Dental Caries microbiology, Fungal Proteins metabolism, Gingivitis microbiology, Mouth microbiology, Periodontitis microbiology, Salivary Proteins and Peptides metabolism
- Abstract
The interactome - the network of protein-protein interactions (PPIs) within a cell or organism - is technically difficult to assess. Bioinformatic tools can, not only, identify potential PPIs that can be later experimentally validated, but also be used to assign functional meaning to PPIs. Saliva's potential as a non-invasive diagnostic fluid is currently being explored by several research groups. But, in order to fully attain its potential, it is necessary to achieve the full characterization of the mechanisms that take place within this ecosystem. The onset of omics technologies, and specifically of proteomics, delivered a huge set of data that is largely underexplored. Quantitative information relative to proteins within a given context (for example a given disease) can be used by computational algorithms to generate information regarding PPIs. These PPIs can be further analyzed concerning their functional meaning and used to identify potential biomarkers, therapeutic targets, defense and pathogenicity mechanisms. We describe a computational pipeline that can be used to identify and analyze PPIs between human and microbial proteins. The pipeline was tested within the scenario of human PPIs of systemic (Zika Virus infection) and of oral conditions (Periodontal disease) and also in the context of microbial interactions (Candida-Streptococcus) and showed to successfully predict functionally relevant PPIs. The pipeline can be applied to different scientific areas, such as pharmacological research, since a functional meaningful PPI network can provide insights on potential drug targets, and even new uses for existing drugs on the market., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2020
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22. Dual RNA Sequencing of Vitis vinifera during Lasiodiplodia theobromae Infection Unveils Host-Pathogen Interactions.
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Gonçalves MFM, Nunes RB, Tilleman L, Van de Peer Y, Deforce D, Van Nieuwerburgh F, Esteves AC, and Alves A
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- Calcium Signaling, Cyclopentanes metabolism, Down-Regulation genetics, Ethylenes biosynthesis, Gene Expression Profiling, Gene Expression Regulation, Plant, Gene Ontology, Genes, Plant, Models, Biological, Oxylipins metabolism, Time Factors, Up-Regulation genetics, Ascomycota physiology, Host-Pathogen Interactions genetics, Plant Diseases genetics, Plant Diseases microbiology, Sequence Analysis, RNA, Vitis genetics, Vitis microbiology
- Abstract
Lasiodiplodia theobromae is one of the most aggressive agents of the grapevine trunk disease Botryosphaeria dieback. Through a dual RNA-sequencing approach, this study aimed to give a broader perspective on the infection strategy deployed by L. theobromae , while understanding grapevine response. Approximately 0.05% and 90% of the reads were mapped to the genomes of L. theobromae and Vitis vinifera , respectively. Over 2500 genes were significantly differentially expressed in infected plants after 10 dpi, many of which are involved in the inducible defense mechanisms of grapevines. Gene expression analysis showed changes in the fungal metabolism of phenolic compounds, carbohydrate metabolism, transmembrane transport, and toxin synthesis. These functions are related to the pathogenicity mechanisms involved in plant cell wall degradation and fungal defense against antimicrobial substances produced by the host. Genes encoding for the degradation of plant phenylpropanoid precursors were up-regulated, suggesting that the fungus could evade the host defense response using the phenylpropanoid pathway. The up-regulation of many distinct components of the phenylpropanoid pathway in plants supports this hypothesis. Moreover, genes related to phytoalexin biosynthesis, hormone metabolism, cell wall modification enzymes, and pathogenesis-related proteins seem to be involved in the host responses observed. This study provides additional insights into the molecular mechanisms of L. theobromae and V. vinifera interactions.
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- 2019
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23. Verrucoconiothyrium ambiguum sp. nov., a novel species isolated from sea water, and affiliation of the genus Verrucoconiothyrium to the family Didymellaceae .
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Gonçalves MFM, Silva BMV, Esteves AC, and Alves A
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- Ascomycota isolation & purification, DNA, Fungal, Mycological Typing Techniques, Portugal, Sequence Analysis, DNA, Spores, Fungal, Ascomycota classification, Phylogeny, Seawater microbiology
- Abstract
The genus Verrucoconiothyrium was erected to accommodate Coniothyrium -like species with verruculose conidia. So far, it includes only four species, which have been found in association with plants, and very little is known about their distribution and host preferences. In this study, a Coniothyrium -like fungus isolated from sea water from the north of Portugal was characterised. Phylogenetic analysis, based on sequence data of the internal transcribed spacer and beta-tubulin loci, placed this fungus within the genus Verrucoconiothyrium but clearly distinct from the other known species. A novel species Verrucoconiothyrium ambiguum sp. nov. is described and illustrated. The taxonomic affiliation of the genus Verrucoconiothyrium at the family level was addressed through individual and combined gene genealogies. Our results show that the genus Verrucoconiothyrium is a member of the family Didymellaceae .
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- 2019
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24. Neptunomyces aureus gen. et sp. nov. (Didymosphaeriaceae, Pleosporales) isolated from algae in Ria de Aveiro, Portugal.
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Gonçalves MFM, Vicente TFL, Esteves AC, and Alves A
- Abstract
A collection of fungi was isolated from macroalgae of the genera Gracilaria , Enteromorpha and Ulva in the estuary Ria de Aveiro in Portugal. These isolates were characterized through a multilocus phylogeny based on ITS region of the ribosomal DNA, beta-tubulin ( tub2 ) and translation elongation factor 1 alpha ( tef1-α ) sequences, in conjunction with morphological and physiological data. These analyses showed that the isolates represented an unknown fungus for which a new genus, Neptunomyces gen. nov. and a new species, Neptunomyces aureus sp. nov. are proposed. Phylogenetic analyses supported the affiliation of this new taxon to the family Didymosphaeriaceae., (Micael F. M. Gonçalves, Tânia F. L. Vicente, Ana C. Esteves, Artur Alves.)
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- 2019
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25. Biodiversity of Penicillium species from marine environments in Portugal and description of Penicillium lusitanum sp. nov., a novel species isolated from sea water.
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Gonçalves MFM, Santos L, Silva BMV, Abreu AC, Vicente TFL, Esteves AC, and Alves A
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- Biodiversity, DNA, Fungal genetics, DNA, Ribosomal Spacer genetics, Penicillium isolation & purification, Portugal, Seaweed microbiology, Sequence Analysis, DNA, Tubulin genetics, Wood microbiology, Penicillium classification, Phylogeny, Seawater microbiology
- Abstract
During an extensive survey of marine fungi in coastal marine environments from Portugal, a collection of Penicillium isolates were obtained from sea water, macroalgae and driftwood. Sixteen distinct Penicillium species were identified with Penicillium terrigenum and Penicillium brevicompactum being the most frequent. A Penicillium species isolated from sea water could not be affiliated to any known species. Phylogenetic analyses based on the ITS region of the rDNA and the beta-tubulin ( benA ) gene placed it into Penicillium section Ramosa , distinct from all currently known species and with Penicillium tunisiense as its closest relative. Although having similar morphological characteristics, these species differ in micromorphological and molecular characters. Thus, Penicillium lusitanum sp. nov. is proposed as a novel species.
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- 2019
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26. A multi-omics analysis of the grapevine pathogen Lasiodiplodia theobromae reveals that temperature affects the expression of virulence- and pathogenicity-related genes.
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Félix C, Meneses R, Gonçalves MFM, Tilleman L, Duarte AS, Jorrín-Novo JV, Van de Peer Y, Deforce D, Van Nieuwerburgh F, Esteves AC, and Alves A
- Subjects
- Ascomycota metabolism, Ascomycota pathogenicity, Fungal Proteins metabolism, Humans, Plant Diseases microbiology, Virulence genetics, Virulence Factors genetics, Virulence Factors metabolism, Vitis microbiology, Ascomycota genetics, Fungal Proteins genetics, Gene Expression Profiling methods, Gene Expression Regulation, Fungal, Proteomics methods, Temperature
- Abstract
Lasiodiplodia theobromae (Botryosphaeriaceae, Ascomycota) is a plant pathogen and human opportunist whose pathogenicity is modulated by temperature. The molecular effects of temperature on L. theobromae are mostly unknown, so we used a multi-omics approach to understand how temperature affects the molecular mechanisms of pathogenicity. The genome of L. theobromae LA-SOL3 was sequenced (Illumina MiSeq) and annotated. Furthermore, the transcriptome (Illumina TruSeq) and proteome (Orbitrap LC-MS/MS) of LA-SOL3 grown at 25 °C and 37 °C were analysed. Proteins related to pathogenicity (plant cell wall degradation, toxin synthesis, mitogen-activated kinases pathway and proteins involved in the velvet complex) were more abundant when the fungus grew at 25 °C. At 37 °C, proteins related to pathogenicity were less abundant than at 25 °C, while proteins related to cell wall organisation were more abundant. On the other hand, virulence factors involved in human pathogenesis, such as the SSD1 virulence protein, were expressed only at 37 °C. Taken together, our results showed that this species presents a typical phytopathogenic molecular profile that is compatible with a hemibiotrophic lifestyle. We showed that L. theobromae is equipped with the pathogenesis toolbox that enables it to infect not only plants but also animals.
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- 2019
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27. Secondary metabolites produced by grapevine strains of Lasiodiplodia theobromae grown at two different temperatures.
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Félix C, Salvatore MM, DellaGreca M, Ferreira V, Duarte AS, Salvatore F, Naviglio D, Gallo M, Alves A, Esteves AC, and Andolfi A
- Subjects
- Ascomycota chemistry, Phylogeny, Ascomycota growth & development, Ascomycota metabolism, Secondary Metabolism, Temperature, Vitis microbiology
- Abstract
Lasiodiplodia theobromae is a fungal plant pathogen that has been associated with Botryosphaeria dieback of grapevine. Despite several studies on L. theobromae , until now the production of secondary metabolites by strains isolated from grapevines has not been reported. The ability of two strains of L. theobromae isolated from grapevine to produce lipophilic metabolites was studied. Although many typical compounds of low molecular weight were identified from the crude extracts of both strains (e.g., lasiolactols, substituted 2-dihydrofuranones, melleins, jasmonic acid, 3-indolcarboxylic acid, botryodiplodins), (2 R /2 S ,3 S ,4 S )-3- epi -botryodiplodin was isolated for the first time as a natural compound. Furthermore, a comparative study of metabolite production was conducted at 25 and 37 C to understand temperature effects on metabolite profiles. Some metabolites were produced only by one strain (e.g., (3 S ,4 S )-4-acetyl-3-methyl-2-dihydrofuranone produced by LA-SOL3) and others only at a specific temperature (e.g., jasmonic acid at 25 C, botryodiplodins at 37 C). Phytotoxicity and cytotoxicity of pure compounds were evaluated to clarify the influence of lipophilic metabolites on the biological activities of culture filtrates of both strains. The most toxic compound for Vero and 3T3 cells was (2 R /2 S ,3 S ,4 S )-3- epi -botryodiplodin.
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- 2019
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28. Production of toxic metabolites by two strains of Lasiodiplodia theobromae, isolated from a coconut tree and a human patient.
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Félix C, Salvatore MM, DellaGreca M, Meneses R, Duarte AS, Salvatore F, Naviglio D, Gallo M, Jorrín-Novo JV, Alves A, Andolfi A, and Esteves AC
- Subjects
- Animals, Ascomycota growth & development, Ascomycota isolation & purification, Cell Line, Chlorocebus aethiops, Cocos microbiology, Cyclopentanes metabolism, Cyclopentanes toxicity, Humans, Metabolome, Mycotoxins biosynthesis, Mycotoxins metabolism, Oxylipins metabolism, Oxylipins toxicity, Phylogeny, Vero Cells, Zearalenone analogs & derivatives, Zearalenone metabolism, Zearalenone toxicity, Ascomycota chemistry, Ascomycota metabolism, Secondary Metabolism, Temperature, Trees microbiology
- Abstract
Lasiodiplodia theobromae is a phytopathogenic fungus that causes diseases not only in a broad number of plant hosts but also occasionally in humans. The capacity of L. theobromae to produce bioactive metabolites at 25 C (environmental mean temperature) and at 37 C (body mean temperature) was investigated. Two strains, CAA019 and CBS339.90, isolated respectively from a coconut tree and a human patient were characterized. The phytotoxicity and cytotoxicity (on mammalian cells) of the secretomes of both strains of L. theobromae were investigated. Also, phytotoxicity and cytotoxicity of pure compounds were evaluated. The phytotoxicity of the secretome of strain CAA019 was higher than the phytotoxicity of the secretome of strain CBS339.90 at 25 C. However, the phytotoxicity for both strains decreased when they were grown at 37 C. Only the secretome of strain CBS339.90 grown at 37 C induced up to 90% Vero and 3T3 cell mortality. This supports the presence of different metabolites in the secretome of strains CAA019 and CBS339.90. Metabolites typical of L. theobromae were isolated and identified from organic extracts of the secretome of both strains (e.g., 3-indolecarboxylic acid, jasmonic acid, lasiodiplodin, four substituted 2-dihydrofuranones, two melleins, and cyclo-(Trp-Ala)). Also, metabolites such as scytalone, not previously reported for this species, were isolated and identified. Metabolite production is affected by strain and temperature. In fact, some metabolites are strain specific (e.g., lasiodiplodin) and some metabolites are temperature specific (e.g., jasmonic acid). Although more strains should be characterized, it may be anticipated that temperature tuning of secondary-metabolite production emerges as a putative contributing factor in the modulation of L. theobromae pathogenicity towards plants, and also towards mammalian cells.
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- 2018
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29. Lasiodiplodia theobromae as a Producer of Biotechnologically Relevant Enzymes.
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Félix C, Libório S, Nunes M, Félix R, Duarte AS, Alves A, and Esteves AC
- Subjects
- Ascomycota enzymology, Cellulase, Enzyme Activation, Enzyme Assays, Enzyme Stability, Extracellular Space, Fermentation, Lipase, Peptide Hydrolases, Temperature, Ascomycota metabolism, Biotechnology methods, Enzymes biosynthesis
- Abstract
Phytopathogenic fungi are known to produce several types of enzymes usually involved in plant cell wall degradation and pathogenesis. The increasing of global temperature may induce fungi, such as Lasiodiplodia theobromae ( L. theobromae ), to alter its behavior. Nonetheless, there is only limited information regarding the effect of temperature on L. theobromae production of enzymes. The need for new, thermostable enzymes, that are biotechnologically relevant, led us to investigate the effect of temperature on the production of several extracellular enzymatic activities by different L. theobromae strains. Fungi were grown at 25 °C, 30 °C and 37 °C and the enzymatic activities were detected by plate assays, quantified by spectrophotometric methods and characterized by zymography. The thermostability (25-80 °C) of the enzymes produced was also tested. Strains CAA019, CBS339.90, LA-SOL3, LA-SV1 and LA-MA-1 produced amylases, gelatinases, caseinases, cellulases, lipases, laccases, xylanases, pectinases and pectin liases. Temperature modulated the expression of the enzymes, and this effect was more visible when fungi were grown at 37 °C than at lower temperatures. Contrary to proteolytic and endoglucanolytic activities, whose highest activities were detected when fungi were grown at 30 °C, lipolytic activity was not detected at this growth temperature. Profiles of proteases and endoglucanases of fungi grown at different temperatures were characterized by zymography. Enzymes were shown to be more thermostable when fungi were grown at 30 °C. Proteases were active up to 50 °C and endoglucanases up to 70 °C. Lipases were the least stable, with activities detected up to 45 °C. The enzymatic profiles detected for L. theobromae strains tested showed to be temperature and strain-dependent, making this species a good target for biotechnological applications., Competing Interests: The authors declare that they have no competing interests.
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- 2018
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30. Photoprotection in a monophyletic branch of chlorophyte algae is independent of energy-dependent quenching (qE).
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Christa G, Cruz S, Jahns P, de Vries J, Cartaxana P, Esteves AC, Serôdio J, and Gould SB
- Subjects
- Chlorophyta growth & development, Chlorophyta radiation effects, Darkness, Light, Stress, Physiological radiation effects, Thermodynamics, Xanthophylls metabolism, Zeaxanthins, Chlorophyta physiology, Photochemical Processes, Phylogeny
- Abstract
Phototrophic organisms need to ensure high photosynthetic performance whilst suppressing reactive oxygen species (ROS)-induced stress occurring under excess light conditions. The xanthophyll cycle (XC), related to the high-energy quenching component (qE) of the nonphotochemical quenching (NPQ) of excitation energy, is considered to be an obligatory component of photoprotective mechanisms. The pigment composition of at least one representative of each major clade of Ulvophyceae (Chlorophyta) was investigated. We searched for a light-dependent conversion of pigments and investigated the NPQ capacity with regard to the contribution of XC and the qE component when grown under different light conditions. A XC was found to be absent in a monophyletic group of Ulvophyceae, the Bryopsidales, when cultivated under low light, but was triggered in one of the 10 investigated bryopsidalean species, Caulerpa cf. taxifolia, when cultivated under high light. Although Bryopsidales accumulate zeaxanthin (Zea) under high-light (HL) conditions, NPQ formation is independent of a XC and not related to qE. qE- and XC-independent NPQ in the Bryopsidales contradicts the common perception regarding its ubiquitous occurrence in Chloroplastida. Zea accumulation in HL-acclimated Bryopsidales most probably represents a remnant of a functional XC. The existence of a monophyletic algal taxon that lacks qE highlights the need for broad biodiversity studies on photoprotective mechanisms., (© 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.)
- Published
- 2017
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31. Temperature Modulates the Secretome of the Phytopathogenic Fungus Lasiodiplodia theobromae.
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Félix C, Duarte AS, Vitorino R, Guerreiro AC, Domingues P, Correia AC, Alves A, and Esteves AC
- Abstract
Environmental alterations modulate host-microorganism interactions. Little is known about how climate changes can trigger pathogenic features on symbiont or mutualistic microorganisms. Current climate models predict increased environmental temperatures. The exposing of phytopathogens to these changing conditions can have particularly relevant consequences for economically important species and for humans. The impact on pathogen/host interaction and the shift on their biogeographical range can induce different levels of virulence in new hosts, allowing massive losses in agricultural and health fields. Lasiodiplodia theobromae is a phytopathogenic fungus responsible for a number of diseases in various plants. It has also been described as an opportunist pathogen in humans, causing infections with different levels of severity. L. theobromae has a high capacity of adaptation to different environments, such as woody plants, moist argillaceous soils, or even humans, being able to grow and infect hosts in a wide range of temperatures (9-39°C). Nonetheless, the effect of an increase of temperature, as predicted in climate change models, on L. theobromae is unknown. Here we explore the effect of temperature on two strains of L. theobromae - an environmental strain, CAA019, and a clinical strain, CBS339.90. We show that both strains are cytotoxic to mammalian cells but while the environmental strain is cytotoxic mainly at 25°C, the clinical strain is cytotoxic mainly at 30 and 37°C. Extracellular gelatinolytic, xylanolytic, amylolytic, and cellulolytic activities at 25 and 37°C were characterized by zymography and the secretome of both strains grown at 25, 30, and 37°C were characterized by electrophoresis and by Orbitrap LC-MS/MS. More than 75% of the proteins were identified, mostly enzymes (glycosyl hydrolases and proteases). The strains showed different protein profiles, which were affected by growth temperature. Also, strain specific proteins were identified, such as a putative f5/8 type c domain protein - known for being involved in pathogenesis - by strain CAA019 and a putative tripeptidyl-peptidase 1 protein, by strain CBS339.90. We showed that temperature modulates the secretome of L. theobromae. This modulation may be associated with host-specificity requirements. We show that the study of abiotic factors, such as temperature, is crucial to understand host/pathogen interactions and its impact on disease.
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- 2016
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32. The impact of obesity on male fecundity: a Brazilian study.
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Dubeux VT, Renovato T, Esteves AC, André L, Oliveira Ad, and Penna IA
- Subjects
- Brazil epidemiology, Cohort Studies, Humans, Male, Sperm Count, Sperm Motility, Waist Circumference, Infertility, Male complications, Infertility, Male epidemiology, Obesity complications, Obesity epidemiology
- Abstract
Introduction: Obesity has become a major problem in most developed countries. Infertility ranks high among the issues brought by excessive weight gain, particularly as it may affect male sexual function. This study investigated a population of Brazilian infertile men in an attempt to establish a relationship between obesity and infertility., Methods: A total of 153 infertile men had their anthropometric data collected and were divided into groups according to their body mass index and waist circumference measurements. Sperm parameters including sperm count, concentration, morphology, and motility were compared., Results: Multivariate analysis failed to show a positive correlation between excessive weight gain or increased waist circumference, and sperm alterations in a population of infertile men., Conclusions: The findings described in this study support the idea that there is no association between obesity and semen alterations in a population of infertile men., Competing Interests: CONFLICT OF INTERESTS No conflict of interest have been declared.
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- 2016
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33. Mesoscopic simulations of hydrophilic cross-linked polycarbonate polyurethane networks: structure and morphology.
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Iype E, Esteves AC, and de With G
- Abstract
Polyurethane (PU) cross-linked networks are frequently used in biomedical and marine applications, e.g., as hydrophilic polymer coatings with antifouling or low-friction properties and have been reported to exhibit characteristic phase separation between soft and hard segments. Understanding this phase-separation behavior is critical to design novel hydrophilic polymer coatings. However, most of the studies on the structure and morphology of cross-linked coatings are experimental, which only assess the phase separation via indirect methods. Herein we present a mesoscopic simulation study of the network characteristics of model hydrophilic polymer networks, consisting of PU with and without methyl-polyethylene glycol (mPEG) dangling chains. The systems are analyzed using a number of tools, such as the radial distribution function, the cross-link point density distribution and the Voronoi volume distribution (of the cross-linking points). The combined results show that the cross-linked networks without dangling chains are rather homogeneous but contain a small amount of clustering of cross-linker molecules. A clear phase separation is observed when introducing the dangling chains. In spite of that, the amount of cross-linker molecules connected to dangling chains only, i.e., not connected to the main network, is relatively small, leading to about 3 wt% extractables. Thus, these cross-linked polymers consist of a phase-separated, yet highly connected network. This study provides valuable guidelines towards new self-healing hydrophilic coatings based on the molecular design of cross-linked networks in direct contact with water or aqueous fluids, e.g., as anti-fouling self-repairing coatings for marine applications.
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- 2016
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34. Bacterial collagenases - A review.
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Duarte AS, Correia A, and Esteves AC
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- Animals, Bacteria classification, Bacteria genetics, Cell Culture Techniques, Collagen chemistry, Collagen genetics, Collagen metabolism, Collagenases chemistry, Collagenases classification, Collagenases therapeutic use, Cosmetics, Food Technology, Gelatinases metabolism, Humans, Matrix Metalloproteinases metabolism, Proteolysis, Bacteria enzymology, Collagenases physiology
- Abstract
Bacterial collagenases are metalloproteinases involved in the degradation of the extracellular matrices of animal cells, due to their ability to digest native collagen. These enzymes are important virulence factors in a variety of pathogenic bacteria. Nonetheless, there is a lack of scientific consensus for a proper and well-defined classification of these enzymes and a vast controversy regarding the correct identification of collagenases. Clostridial collagenases were the first ones to be identified and characterized and are the reference enzymes for comparison of newly discovered collagenolytic enzymes. In this review we present the most recent data regarding bacterial collagenases and overview the functional and structural diversity of bacterial collagenases. An overall picture of the molecular diversity and distribution of these proteins in nature will also be given. Particular aspects of the different proteolytic activities will be contextualized within relevant areas of application, mainly biotechnological processes and therapeutic uses. At last, we will present a new classification guide for bacterial collagenases that will allow the correct and straightforward classification of these enzymes.
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- 2016
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35. Protein profiles of Escherichia coli and Staphylococcus warneri are altered by photosensitization with cationic porphyrins.
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Alves E, Esteves AC, Correia A, Cunha Â, Faustino MA, Neves MG, and Almeida A
- Subjects
- Cell Survival drug effects, Electrophoresis, Polyacrylamide Gel, Models, Biological, Molecular Structure, Photochemotherapy, Photosensitizing Agents pharmacology, Escherichia coli drug effects, Gene Expression Regulation, Bacterial drug effects, Porphyrins pharmacology, Staphylococcus drug effects
- Abstract
Oxidative stress induced by photodynamic treatment of microbial cells causes irreversible damages to vital cellular components such as proteins. Photodynamic inactivation (PDI) of bacteria, a promising therapeutic approach for the treatment of superficial and localized skin and oral infections, can be achieved by exciting a photosensitizing agent with visible light in an oxygenated environment. Although some studies have addressed the oxidative alterations of PDI in bacterial proteins, the present study is the first to compare the electrophoretic profiles of proteins of Gram-positive and Gram-negative bacteria, having two structurally different porphyrins, with different kinetics of photoinactivation. The cationic porphyrins 5,10,15-tris(1-methylpyridinium-4-yl)-20-(pentafluorophenyl)porphyrin tri-iodide (Tri-Py(+)-Me-PF) and 5,10,15,20-tetrakis(1-methylpyridinium-4-yl)porphyrin tetra-iodide (Tetra-Py(+)-Me) were used to photosensitize Escherichia coli and Staphylococcus warneri upon white light irradiation at an irradiance of 4.0 mW cm(-2). After different photosensitization periods, proteins were extracted from bacteria and analyzed using one-dimensional SDS-PAGE. Apparent molecular weights and band intensities were determined after an irradiation period corresponding to a reduction of 4 log10 in cell viability. After photodynamic treatment, there was a general loss of bacterial proteins, assigned to large-scale protein degradation. Protein loss was more pronounced after PDI with Tri-Py(+)-Me-PF in both bacteria. There was also an increase in the concentration of some proteins as well as an increase in the molecular weight of other proteins. We show that proteins of E. coli and S. warneri are important targets of PDI. Although there is an attempt of cellular response to the PDI-induced damage by overexpression of a limited number of proteins, the damage is lethal. Our results show that changes occurring in the protein pattern during photodynamic treatment are different with the two photosensitizers, which helps to explain the different inactivation kinetics of the two bacteria. SDS-PAGE is a rational approach to assign the type of cellular response to stress that is being induced in the cells.
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- 2015
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36. Toothbrush Handles Individually Adapted for Use by Elderly Patients to Reduce Biofilm on Complete Dentures: A Pilot Study.
- Author
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Kammers AC, Zanetti AL, Lacerda TE, Aroca JP, Camilotti V, and Mendonça MJ
- Abstract
Introduction: Reduction of biofilm on dentures is important for maintaining denture wearers' health., Objective: The aim of this study was to assess the effectiveness of toothbrush handles individually adapted in reducing of biofilm on dentures., Materials and Methods: Study participants were 16 residents of the condo for the elderly, denture wearers, functionally independent and without cognitive impairment. Participants were randomly divided into two groups: Group 1 (adapted toothbrush handles) and Group 2 (conventional toothbrush). Biofilm from the inner surface of the basal area of the denture was observed using 5% erythrosine. Images obtained before starting the use of toothbrushes, after 7 and 21 days were sent for computer analysis., Results: The average amount of biofilm on the first day was considered severe in both groups. At the end of the experiment, the average biofilm coverage in Group 1 was 44.7% (13.1% reduction) and in Group 2 it was 48.6% (4.8% reduction). However, the Friedman analysis of variance test showed that the reduction was statistically significant (p< 0.05) only in Group 1, demonstrating the effectiveness of the adapted brushes., Conclusion: The findings of this pilot study indicated that for the reduction of biofilm on dentures the adapted toothbrush handles were superior to the conventional type.
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- 2015
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37. Novel linear polymers able to inhibit bacterial quorum sensing.
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Cavaleiro E, Duarte AS, Esteves AC, Correia A, Whitcombe MJ, Piletska EV, Piletsky SA, and Chianella I
- Subjects
- Acyl-Butyrolactones chemistry, Aeromonas hydrophila growth & development, Animals, Biofilms drug effects, Biofilms growth & development, Cell Death drug effects, Chlorocebus aethiops, Chromatography, Gel, Colony Count, Microbial, Luminescence, Magnetic Resonance Spectroscopy, Phenotype, Polymerization, Polymers chemical synthesis, Polymers chemistry, Vero Cells, Vibrio physiology, Aeromonas hydrophila drug effects, Polymers pharmacology, Quorum Sensing drug effects, Vibrio drug effects
- Abstract
Bacterial phenotypes, such as biofilm formation, antibiotic resistance and virulence expression, are associated with quorum sensing. Quorum sensing is a density-dependent regulatory system of gene expression controlled by specific signal molecules, such as N-acyl homoserine lactones (AHLs), produced and released by bacteria. This study reports the development of linear polymers capable to attenuate quorum sensing by adsorption of AHLs. Linear polymers were synthesized using MMA as backbone monomer and methacrylic acid and itaconic acid as functional monomers. Two different quorum sensing-controlled phenotypes, Vibrio fischeri bioluminescence and Aeromonas hydrophila biofilm formation, were evaluated to test the polymers' efficiency. Results showed that both phenotypes were significantly affected by the polymers, with the itaconic acid-containing material being more effective than the methacrylic acid one. The polymer inhibitory effects were reverted by the addition of lactones, confirming attenuation of quorum sensing through sequestration of signal molecules. The polymers also showed no cytotoxicity when tested using a mammalian cell line., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
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- 2015
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38. Aeromonas piscicola AH-3 expresses an extracellular collagenase with cytotoxic properties.
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Duarte AS, Cavaleiro E, Pereira C, Merino S, Esteves AC, Duarte EP, Tomás JM, and Correia AC
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- Aeromonas hydrophila genetics, Aeromonas hydrophila metabolism, Animals, Base Sequence, Cell Line, Chlorocebus aethiops, Clostridium enzymology, Clostridium metabolism, DNA, Bacterial genetics, Molecular Sequence Data, Protein Structure, Tertiary, Sequence Analysis, DNA, Vero Cells, Aeromonas hydrophila enzymology, Collagen metabolism, Microbial Collagenase genetics, Microbial Collagenase metabolism
- Abstract
Unlabelled: The aim of this study was to investigate the presence and the phenotypic expression of a gene coding for a putative collagenase. This gene (AHA_0517) was identified in Aeromonas hydrophila ATCC 7966 genome and named colAh. We constructed and characterized an Aeromonas piscicola AH-3::colAh knockout mutant. Collagenolytic activity of the wild-type and mutant strains was determined, demonstrating that colAh encodes for a collagenase. ColAh-collagen interaction was assayed by Far-Western blot, and cytopathic effects were investigated in Vero cells. We demonstrated that ColAh is a gluzincin metallopeptidase (approx. 100 kDa), able to cleave and physically interact with collagen, that contributes for Aeromonas collagenolytic activity and cytotoxicity. ColAh possess the consensus HEXXH sequence and a glutamic acid as the third zinc binding positioned downstream the HEXXH motif, but has low sequence similarity and distinct domain architecture to the well-known clostridial collagenases. In addition, these results highlight the importance of exploring new microbial collagenases that may have significant relevance for the health and biotechnological industries., Significance and Impact of the Study: Collagenases play a central role in processes where collagen digestion is needed, for example host invasion by pathogenic micro-organisms. We identified a new collagenase from Aeromonas using an integrated in silico/in vitro strategy. This enzyme is able to bind and cleave collagen, contributes for AH-3 cytotoxicity and shares low similarity with known bacterial collagenases. This is the first report of an enzyme belonging to the gluzincin subfamily of the M9 family of peptidases in Aeromonas. This study increases the current knowledge on collagenolytic enzymes bringing new perspectives for biotechnology/medical purposes., (© 2014 The Society for Applied Microbiology.)
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- 2015
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39. SDS-PAGE and IR spectroscopy to evaluate modifications in the viral protein profile induced by a cationic porphyrinic photosensitizer.
- Author
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Costa L, Esteves AC, Correia A, Moreirinha C, Delgadillo I, Cunha Â, Neves MG, Faustino MA, and Almeida A
- Subjects
- Coliphages isolation & purification, Electrophoresis, Polyacrylamide Gel, Protein Binding, Spectrophotometry, Infrared, Coliphages chemistry, Coliphages drug effects, Photosensitizing Agents metabolism, Porphyrins metabolism, Viral Proteins analysis
- Abstract
Reactive oxygen species can be responsible for microbial photodynamic inactivation due to its toxic effects, which include severe damage to proteins, lipids and nucleic acids. In this study, the photo-oxidative modifications of the proteins of a non-enveloped T4-like bacteriophage, induced by the cationic porphyrin 5,10,15-tris(1-methylpyridinium-4-yl)-20-(pentafluorophenyl)porphyrin tri-iodide were evaluated. Two methods were used: sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and infrared spectroscopy. SDS-PAGE analysis showed that the phage protein profile was considerably altered after photodynamic treatment. Seven protein bands putatively corresponding to capsid and tail tube proteins were attenuated and two other were enhanced. Infrared spectroscopy confirmed the time-dependent alteration on the phage protein profile detected by SDS-PAGE, indicative of a response to oxidative damage. Infrared analysis showed to be a promising and rapid screening approach for the analysis of the modifications induced on viral proteins by photosensitization. In fact, one single infrared spectrum can highlight the changes induced to all viral molecular structures, overcoming the delays and complex protocols of the conventional methods, in a much simple and cost effective way., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
40. Secretome analysis identifies potential virulence factors of Diplodia corticola, a fungal pathogen involved in cork oak (Quercus suber) decline.
- Author
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Fernandes I, Alves A, Correia A, Devreese B, and Esteves AC
- Subjects
- Ascomycota chemistry, Ascomycota genetics, Ascomycota isolation & purification, Electrophoresis, Gel, Two-Dimensional, Fungal Proteins chemistry, Fungal Proteins genetics, Molecular Sequence Data, Protein Transport, Proteomics, Virulence Factors chemistry, Virulence Factors genetics, Ascomycota metabolism, Fungal Proteins metabolism, Plant Diseases microbiology, Quercus microbiology, Virulence Factors metabolism
- Abstract
The characterisation of the secretome of phytopathogenic fungi may contribute to elucidate the molecular mechanisms of pathogenesis. This is particularly relevant for Diplodia corticola, a fungal plant pathogen belonging to the family Botryosphaeriaceae, whose genome remains unsequenced. This phytopathogenic fungus is recognised as one of the most important pathogens of cork oak, being related to the decline of cork oak forests in the Iberian Peninsula. Unfortunately, secretome analysis of filamentous fungi is limited by the low protein concentration and by the presence of many interfering substances, such as polysaccharides, which affect the separation and analysis by 1D and 2D gel electrophoresis. We compared six protein extraction protocols concerning their suitability for further application with proteomic workflows. The protocols involving protein precipitation were the most efficient, with emphasis on TCA-acetone protocol, allowing us to identify the most abundant proteins on the secretome of this plant pathogen. Approximately 60% of the spots detected were identified, all corresponding to extracellular proteins. Most proteins identified were carbohydrate degrading enzymes and proteases that may be related to D. corticola pathogenicity. Although the secretome was assessed in a noninfection environment, potential virulence factors such as the putative glucan-β-glucosidase, neuraminidase, and the putative ferulic acid esterase were identified. The data obtained forms a useful basis for a deeper understanding of the pathogenicity and infection biology of D. corticola. Moreover, it will contribute to the development of proteomics studies on other members of the Botryosphaeriaceae., (Copyright © 2014 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
41. Botryosphaeriales fungi produce extracellular enzymes with biotechnological potential.
- Author
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Esteves AC, Saraiva M, Correia A, and Alves A
- Subjects
- Cellulases isolation & purification, Fungi classification, Hydrolases isolation & purification, Lipase isolation & purification, Peptide Hydrolases isolation & purification, Fungi enzymology, Industrial Microbiology
- Abstract
Phytopathogenic fungi are known for producing an arsenal of extracellular enzymes whose involvement in the infection mechanism has been suggested. However, these enzymes are largely unknown and their biotechnological potential also remains poorly understood. In this study, the production and thermostability of extracellular enzymes produced by phytopathogenic Botryosphaeriaceae was investigated. Hydrolytic and oxidative activities were detected and quantified at different temperatures. Most strains (70%; 37/53) were able to produce simultaneously cellulases, laccases, xylanases, pectinases, pectin lyases, amylases, lipases, and proteases. Surprisingly for mesophilic filamentous fungi, several enzymes proved to be thermostable: cellulases from Neofusicoccum mediterraneum CAA 001 and from Dothiorella prunicola CBS 124723, lipases from Diplodia pinea (CAA 015 and CBS 109726), and proteases from Melanops tulasnei CBS 116806 were more active at 70 °C than at any of the other temperatures tested. In addition, lipases produced by Diplodia pinea were found to be significantly more active than any other known lipase from Botryosphaeriales. The thermal activity profile and the wide array of activities secreted by these fungi make them optimal producers of biotechnologically relevant enzymes that may be applied in the food and the health industries (proteases), the pulp-and-paper and biofuel industries (cellulases), or even in the detergent industry (lipases, proteases, amylases, and cellulases).
- Published
- 2014
- Full Text
- View/download PDF
42. Self-replenishing ability of cross-linked low surface energy polymer films investigated by a complementary experimental-simulation approach.
- Author
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Esteves AC, Lyakhova K, van Riel JM, van der Ven LG, van Benthem RA, and de With G
- Subjects
- Surface Properties, Cross-Linking Reagents chemistry, Molecular Dynamics Simulation, Polyesters chemistry, Polyurethanes chemistry
- Abstract
Nowadays, many self-healing strategies are available for recovering mechanical damage of bulk polymeric materials. The recovery of surface-dependent functionalities on polymer films is, however, equally important and has been less investigated. In this work we study the ability of low surface energy cross-linked poly(ester urethane) networks containing perfluorinated dangling chains to self-replenish their surface, after being submitted to repeated surface damage. For this purpose we used a combined experimental-simulation approach. Experimentally, the cross-linked films were intentionally damaged by cryo-microtoming to remove top layers and create new surfaces which were characterized by water Contact Angle measurements and X-Ray Photoelectron Spectroscopy. The same systems were simultaneously represented by a Dissipative Particles Dynamics simulation method, where the damage was modeled by removing the top film layers in the simulation box and replacing it by new "air" beads. The influence of different experimental parameters, such as the concentration of the low surface energy component and the molecular mobility span of the dangling chains, on the surface recovery is discussed. The combined approach reveals important details of the self-replenishing ability of damaged polymer films such as the occurrence of multiple-healing events, the self-replenishing efficiency, and the minimum "healing agent" concentration for a maximum recovery.
- Published
- 2014
- Full Text
- View/download PDF
43. Nucleation and growth of monodisperse silica nanoparticles.
- Author
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Carcouët CC, van de Put MW, Mezari B, Magusin PC, Laven J, Bomans PH, Friedrich H, Esteves AC, Sommerdijk NA, van Benthem RA, and de With G
- Abstract
Although monodisperse amorphous silica nanoparticles have been widely investigated, their formation mechanism is still a topic of debate. Here, we demonstrate the formation of monodisperse nanoparticles from colloidally stabilized primary particles, which at a critical concentration undergo a concerted association process, concomitant with a morphological and structural collapse. The formed assemblies grow further by addition of primary particles onto their surface. The presented mechanism, consistent with previously reported observations, reconciles the different theories proposed to date.
- Published
- 2014
- Full Text
- View/download PDF
44. Is swimming able to maintain bone health and to minimize postmenopausal bone resorption?
- Author
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Barreto TK, Bizarria FS, Coutinho MP, Silveira PV, da Silva Kde C, Esteves AC, and de Moraes SR
- Subjects
- Animals, Animals, Newborn, Female, Postmenopause, Rats, Rats, Wistar, Bone Resorption prevention & control, Swimming
- Abstract
Objective: We studied the effect of swimming on the somatic and bone growth of female rats., Methods: 40 neonate Wistar female rats were separated into: monosodium glutamate group (GluM, n = 20) and received MSG solution (4.0 mg/g) on alternate days during the first 14 days after birth, and Saline group (SAL, n = 20) which received saline solution for the same period of time and at the same dose.At 60 days of age, GluM group was ovariectomized (GluMO) and SAL group just suffered surgical stress. Subsequently, half the animals in each group started swimming, resulting in groups: sedentary saline (SALsed, n = 10), swimming saline (SALswi, n = 10), sedentary ovariectomized Glutamate (GluMOsed, n = 10) and swimming ovariectomized Glutamate (GluMOswi, n = 10). At the end of the experiment, we measured the animals' longitudinal length and weight; their radius was weighed and its length measured., Results: The animals of the GluMOsed group had lower body weight and longitudinal length compared to SALsed. Swimming decreased body weight, but had no influence on the longitudinal length of the GluMOswi group compared to GluMOsed group. Longitudinal length and body weight were lower in SALswi animals compared to SALsed animals. Radius weight and length of GluMOsed animals were lower than in SALsed animals. There was no difference in these parameters between GluMOsed and GluMOswi groups; however, these parameters were lower in SALswi animals compared to SALsed animals., Conclusion: Swimming does not influence previously affected bone tissue during the neonatal period, however it may cause damage to healthy bone tissue.
- Published
- 2014
45. Effects of UV radiation on the lipids and proteins of bacteria studied by mid-infrared spectroscopy.
- Author
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Santos AL, Moreirinha C, Lopes D, Esteves AC, Henriques I, Almeida A, Domingues MR, Delgadillo I, Correia A, and Cunha A
- Subjects
- Acinetobacter metabolism, Electrophoresis, Polyacrylamide Gel, Pseudomonas metabolism, Spectrophotometry, Infrared, Lipids chemistry, Proteins chemistry, Ultraviolet Rays
- Abstract
Knowledge of the molecular effects of UV radiation (UVR) on bacteria can contribute to a better understanding of the environmental consequences of enhanced UV levels associated with global climate changes and will help to optimize UV-based disinfection strategies. In the present work, the effects of exposure to UVR in different spectral regions (UVC, 100-280 nm; UVB, 280-320 nm; and UVA, 320-400 nm) on the lipids and proteins of two bacterial strains ( Acinetobacter sp. strain PT5I1.2G and Pseudomonas sp. strain NT5I1.2B) with distinct UV sensitivities were studied by mid-infrared spectroscopy. Exposure to UVR caused an increase in methyl groups associated with lipids, lipid oxidation, and also led to alterations in lipid composition, which were confirmed by gas chromatography. Additionally, mid-infrared spectroscopy revealed the effects of UVR on protein conformation and protein composition, which were confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), oxidative damage to amino acids, and changes in the propionylation, glycosylation and/or phosphorylation status of cell proteins. Differences in the targets of UVR in the two strains tested were identified and may explain their discrepant UV sensitivities. The significance of the results is discussed from an ecological standpoint and with respect to potential improvements in UV-based disinfection technologies.
- Published
- 2013
- Full Text
- View/download PDF
46. Temperature-triggered collection and release of water from fogs by a sponge-like cotton fabric.
- Author
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Yang H, Zhu H, Hendrix MM, Lousberg NJ, de With G, Esteves AC, and Xin JH
- Published
- 2013
- Full Text
- View/download PDF
47. Phylogenetic diversity, antibiotic resistance and virulence traits of Aeromonas spp. from untreated waters for human consumption.
- Author
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Carvalho MJ, Martínez-Murcia A, Esteves AC, Correia A, and Saavedra MJ
- Subjects
- Aeromonas genetics, Aeromonas pathogenicity, DNA Gyrase genetics, Drug Resistance, Microbial genetics, Humans, Integrons genetics, Portugal, Virulence genetics, Aeromonas classification, Aeromonas drug effects, Anti-Bacterial Agents pharmacology, Biodiversity, Phylogeny, Water Microbiology, Water Quality
- Abstract
It is well known that water constitutes an important contamination route for microorganisms. This is especially true for Aeromonas which are widespread in untreated and treated waters. In this study, Portuguese untreated waters not regularly monitored were screened for the presence and diversity of aeromonads. A total of 206 isolates were discriminated by RAPD-PCR and 80 distinct strains were identified by gyrB based phylogenetic analysis. The most frequently detected species were Aeromonas hydrophila, Aeromonas bestiarum and Aeromonas media. The antibiotic susceptibility profile of these strains was determined and showed a typical profile of the genus. Nonetheless, the percentage of resistant strains to tetracycline, chloramphenicol and/or trimethoprim/sulfamethoxazole was lower than that reported for clinical isolates and isolates recovered from aquacultures and other environments historically subjected to antibiotic contamination. This suggests that the existence of such pressures in those environments selects for resistant Aeromonas. A similar trend for integron presence was found. Genes coding for CphA and TEM, and tet(A), (E), (C) or (D) genes were found in 28%, 1%, and 10% of the strains, respectively. 10% of the strains contained an integron. Variable regions of seven class 1 integrons and one class 2 integron were characterised. Furthermore, strains displayed virulence related phenotypes such as extracellular lipolytic and proteolytic activities as well as aerolysin related genes (43% of strains). The ascV and aexT genes were found in 16% and 3% of strains respectively and, in some cases, concomitantly in the same specimen. This study shows that diverse Aeromonas spp. presenting distinct antibiotic resistance features and putative virulence traits are frequently present in waters for human and animal consumption in Portugal. Genes associated to antibiotic resistance and microbial virulence previously identified in organisms with human health significance were detected in these aeromonads, suggesting that these waters may act as a pivotal route for infections., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
48. Self-replenishing surfaces.
- Author
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Dikić T, Ming W, van Benthem RA, Esteves AC, and de With G
- Subjects
- Biocompatible Materials chemistry, Electronics, Hydrophobic and Hydrophilic Interactions, Polyesters chemistry, Solar Energy, Surface Properties, Temperature, Polymers chemistry
- Abstract
Damaged surfaces self-replenish their chemical composition by the spontaneous re-orientation of functional groups chemically bonded to the polymer network. The repair of the surface chemistry leads to the recovery of surface functionality. This self-replenishing approach is suitable to recover many surface-related properties and constitutes a major breakthrough in extending the service life-time of functional materials., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2012
- Full Text
- View/download PDF
49. Functional and conformational changes in the aspartic protease cardosin A induced by TFE.
- Author
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Fraga AS, Esteves AC, Micaelo N, Cruz PF, Brito RM, Nutley M, Cooper A, Barros MM, and Pires EM
- Subjects
- Catalytic Domain drug effects, Computer Simulation, Enzyme Activation drug effects, Models, Molecular, Protein Conformation drug effects, Spectrometry, Fluorescence, Aspartic Acid Endopeptidases chemistry, Aspartic Acid Endopeptidases metabolism, Plant Proteins chemistry, Plant Proteins metabolism, Trifluoroethanol pharmacology
- Abstract
Conformational and functional changes of cardosin A, an aspartic protease of vegetal origin, in the presence of 2,2,2-trifluoroethanol (TFE), were assessed. TFE induced alterations of cardosin activity and conformation that differed with the solvent concentration. MD simulations showed that there are significant local alterations in protein flexibility and TFE molecules were found to replace several hydration molecules in the active site of the enzyme. This may explain some of the activity loss observed in the presence of TFE, especially at low TFE concentrations, as well as the recovery of enzyme activity upon aqueous dilution, indicating the release of the TFE molecules from the active site., (Copyright © 2011 Elsevier B.V. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
50. [Inherited aplastic anemias].
- Author
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Esteves AC, Freitas O, Almeida T, and Rosado L
- Subjects
- Anemia, Aplastic diagnosis, Child, Child, Preschool, Female, Humans, Male, Anemia, Aplastic genetics
- Abstract
The inherited aplastic anaemias are a heterogeneous group of disorders characterized by bone marrow failure, frequent association with one or more somatic anomalies and increased risk of cancer. They are rare disorders, usually diagnosed at paediatric age, and have significant premature mortality. The authors report 11 cases of inherited aplastic anaemias, 8 of Fanconi's anaemia and 3 of Dyskeratosis congenita. These cases were diagnosed in the last 14 years in the Dona Estefânia Hospital., (2009 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
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