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INTRODUCTION: Previous research has shown that personality traits and gaming motives are important predictors for explaining regular and disordered gaming. However, the mediating role of gaming motives in the relation between personality traits and video game outcomes (e.g., time spent gaming or disordered gaming) has been scarcely studied and limited cross-national studies have addressed this issue. The present study aimed to examine the direct and indirect effects of the Big Five personality traits on weekly gaming and disordered gaming via gaming motives across seven countries. METHOD: 3540 college student gamers (59.5% women) from the U.S., Canada, Spain, Argentina, Uruguay, South Africa and England completed the online survey. Structural equation modeling was conducted to test models. Multigroup models were employed to test model invariance across countries. RESULTS: Significant, albeit weak, relations were found between personality traits and gaming outcomes, and were mediated mostly by coping motives in predicting disordered gaming, and by social interaction and recreation (to a lesser extent) motives in predicting weekly gaming. Some minor, yet significant, differences across countries appeared and are discussed in detail. DISCUSSION: The present findings indicate that the differential interrelations between personality traits, gaming motives, and video gaming outcomes may be generalized in college students across countries.
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Motivação , Personalidade , Estudantes , Jogos de Vídeo , Humanos , Feminino , Masculino , Estudantes/psicologia , Adulto Jovem , Jogos de Vídeo/psicologia , Canadá , Estados Unidos , Universidades , Adolescente , Espanha , África do Sul , Uruguai , Inglaterra , Argentina , Adulto , Comparação Transcultural , Transtorno de Adição à Internet/psicologia , Transtorno de Adição à Internet/epidemiologia , Adaptação PsicológicaRESUMO
Multimorbidity is defined as the presence of two or more chronic medical conditions in a person, whether physical, mental or long-term infectious diseases. This is especially common in older populations, affecting their quality of life and emotionally impacting their caregivers and family. Technology can allow for monitoring, managing, and motivating older adults in their self-care, as well as supporting their caregivers. However, when several conditions are present at once, it may be necessary to manage several types of technologies, or for technology to manage the interaction between conditions. This work aims to understand and describe the technologies that are used to support the management of multimorbidity for older adults. We conducted a systematic review of ten years of scientific literature from four online databases. We reviewed a corpus of 681 research papers, finally including 25 in our review. The technologies used most frequently by older adults with multimorbidity are mobile applications and websites, and they are mostly focused on communication and connectivity. We then propose opportunities for future research on addressing the challenges in the management of several simultaneous health conditions, potentially creating a better approach than managing each condition as if it were independent.
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Quantifying drought's economic impacts has been key for decision-making to build future strategies and improve the development and implementation of proactive plans. However, climate change is changing drought frequency, intensity, and durability. These changes imply modifications of their economic impact, as longer droughts result in greater cumulative economic losses for water users. Though the longer the drought lasts, other factors also play a crucial role in its economic outcomes, such as Infrastructure capacity (IC), the Amount of Water in Storage (AWS) in reservoirs and aquifers, and short- and long-term responses to it. This study proposes and applies an analytical framework for the economic assessment of long-run droughts, assessing and explaining central Chile megadrought economic effects through the factors that begin to influence the economic impact level in this setting. High levels of both IC and the AWS, as well as short- and long-term responses of water users, allow for high resilience to long-run droughts, tolerating extraordinary water disruption in its society with relatively low total economic impacts. Despite this adaptability, long-term droughts bring places to a water-critical threshold where long-term adaptation strategies may be less flexible than short-term strategies, escalating the adverse economic effects. This fact suggests that the economic evaluation of megadrought needs to focus on future tipping points (substantial water scarcity). The tipping point depends on the IC, how water users manage the AWS, and adaptation strategies. Establishing the tipping point should be a priority for future interdisciplinary research.
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Secas , Abastecimento de Água , Água , Chile , Mudança ClimáticaRESUMO
INTRODUCTION: Gaming motives appear to be an important predictor of time spent gaming and disordered gaming. The Videogaming Motives Questionnaire (VMQ) has shown adequate psychometric properties to assess gaming motives among Spanish college students. However, the utility of this measure has not yet been explored in other cultures. This research aimed to examine the structure and measurement invariance of the VMQ across seven countries and gender groups, and to provide criterion-related validity evidence for VMQ scores. METHOD: College students who reported having played videogames in the last year (n = 5192; 59.07 % women) from the US, Canada, South Africa, Spain, Argentina, England, and Uruguay completed an online survey to measure time spent gaming, disordered gaming, and the VMQ. RESULTS: Findings support a 24-item 8-intercorrelated factor model structure for the VMQ in the total sample. Our results also support configural, metric, and scalar invariance of the VMQ across gender groups and countries. Students from North America (US and Canada) scored higher on most gaming motives (except recreation and cognitive development) than students from the other countries. The correlations between VMQ and non-VMQ variables were similar across gender and countries, except in England where VMQ correlations with time spent gaming were stronger. DISCUSSION: These results suggest that the VMQ is a useful measure for assessing gaming motives across young adults from different countries.
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Jogos de Vídeo , Adulto Jovem , Humanos , Feminino , Masculino , Reprodutibilidade dos Testes , Universidades , Psicometria , Inquéritos e QuestionáriosRESUMO
Endophytic fungi are a highly diverse group of fungi that intermittently colonize all plants without causing symptoms of the disease. They sense and respond to physiological and environmental changes of their host plant and microbiome. The inter-organism interactions are largely driven by chemical networks mediated by specialized metabolites. The balance of these complex interactions leads to healthy and strong host plants. Endophytic strains have particular machinery to produce a plethora of secondary metabolites with a variety of bioactivities and unknown functions in an ecological niche. Terpenoids play a key role in endophytism and represent an important source of bioactive molecules for human health and agriculture. In this review, we describe the role of endophytic fungi in plant health, fungal terpenoids in multiple interactions, and bioactive fungal terpenoids recently reported from endophytes, mainly from plants used in traditional medicine, as well as from algae and mangroves. Additionally, we highlight endophytic fungi as producers of important chemotherapeutic terpenoids, initially discovered in plants. Despite advances in understanding endophytism, we still have much to learn in this field. The study of the role, the evolution of interactions of endophytic fungi and their terpenoids provide an opportunity for better applications in human health and agriculture.
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Raman spectroscopy, transmission electron microscopy (TEM) and atomic force microscopy (AFM) techniques can perform chemical analyses and acquire high-resolution images of cell samples. For this reason, in this study, semi-thin sections of a single Penicillium rubens cell were analysed by Raman enhanced surface spectroscopy. The spectra showed peaks corresponding to the macromolecules that make up the cellular components. In addition, the various organelles were analysed by TEM and AFM to observe the cellular nanostructures. With the use of these techniques, it is possible to identify molecules in semi-thin sections, which provides a wide potential for biomedical applications and for the analysis of cell dynamics. The observation of the most detailed possible structure of cells is used as a starting point in numerous studies to identify and localise some biochemical processes. Given that the function of eukaryotic cells depends on the location, shape, structure and function of the subcellular organelles (and on the interaction between them), the sum of the data obtained allows a complete analysis of what happens in the cell. This article addresses, from a multidisciplinary point of view, what happens in a single cell of a filamentous fungus (Penicillium rubens) while it is in a physiological moment (secondary metabolism) that allows the biosynthesis of an antibiotic (penicillin). For this purpose, different types of microscopies were used (TEM: transmission electron microscopy, and AFM: atomic force microscopy, which allow visualising small details in the cell) and a spectroscopy method (Raman, which allows detecting certain characteristics of the macromolecules and some stretching bonds). Regarding the results, during the synthesis of penicillin, the antibiotic-producing Penicillium rubens cells showed significant changes compared to the non-producing cells: the cell wall is observed to be significantly thickened in the production phase, organelles such as peroxisomes grow in number and size since it is known that the final route of metabolite synthesis takes place in them. When penicillin is released from peroxisomes, they must be degraded to release the load from the cell; this is done by vacuoles, which are active and engulf peroxisomes. The newly synthesised penicillin is found within secretory vesicles that travel towards the cell membrane and both membranes fuse creating ripples. On the other hand, and given that a single cell is being studied, it is essential to increase the signal to detect biomolecules employing the Raman-SERS technique, using a silver substrate to obtain the increased signal.
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Penicilinas , Penicillium , Antibacterianos/metabolismo , Penicilinas/metabolismo , Penicillium/metabolismo , Penicillium/ultraestrutura , Análise Espectral RamanRESUMO
Infection with Helicobacter pylori is one of the most important risk factors for developing gastric cancer (GC). The type IV secretion system (T4SS) encoded in the cag pathogenicity island is the main virulence factor of H. pylori associated with GC. Additionally, other virulence factors have been shown to play a role in the H. pylori virulence, such as vacuolizing cytotoxin (VacA), urease, flagella, and adhesins. Long-chain fatty acids (LCFAs) are signaling molecules that affect the transcription of virulence genes in several pathogenic bacteria such as Salmonella enterica, Vibrio cholerae, Pseudomonas aeruginosa and Mycobacterium tuberculosis. However, the effect of LCFAs on the transcription of H. pylori virulence and regulatory genes remains unknown. Here we analyzed whether the transcription of virulence genes that encode T4SS and cellular envelope components, flagellins, adhesins, toxins, urease, as well as the transcription of different regulatory genes of the H. pylori strain 26695, are altered by the presence of five distinct LCFAs: palmitic, stearic, oleic, linoleic, and linolenic acids. Palmitic and oleic acids up-regulated the transcription of most of the virulence genes tested, including cagL, cagM, flaB, sabA, mraY and vacA, as well as that of the genes encoding the transcriptional regulators NikR, Fur, CheY, ArsR, FlgR, HspR, HsrA, Hup, and CrdR. In contrast, the other LCFAs differentially affected the transcription of the virulence and regulatory genes assessed. Our data show that LCFAs can act as signaling molecules that control the transcription of the H. pylori virulome.
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Anthropogenic land use change (ALUC) satisfies human needs but also impacts aquatic ecosystems. Aquatic ecosystems are intrinsically linked with terrestrial landscapes, an association that is already recognized as a key factor to address future research and effective governance. However, the complexity and range of the impact of ALUC in aquatic ecosystems have been fundamental challenges and have implicitly routed the analysis to particular segments, drivers, management, or effects of the theme. In this study, we present an attempt to frame the subject in a broader context through a topic-based bibliometric analysis. Our aim is to identify possible biases and gaps in the current scientific literature and detect the main topics that have characterized the theme. Our results show an unequal distribution of articles by country when we analyzed the authors' affiliation and also a slight increase in contributions from social and economic disciplines, although they are still underrepresented. Moreover, we distinguish topics whose prevalence seems to change, especially those topics where the use of scenario analysis and multi-stressors are considered. We discuss the main biases and gaps revealed by our results, concluding that future studies on the impact of ALUC on aquatic ecosystems should better integrate social and economic disciplines and expand geographic frontiers.
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Bibliometria , Ecossistema , Viés , HumanosRESUMO
Electroporation is a method for the introduction of molecules (usually nucleic acids) into a cell, consisting of submitting the cells to high-voltage and short electric pulses in the presence of the exogenous DNA/molecule. It is a versatile method, adaptable to different types of cells, from bacteria to cultured cells to higher eukaryotes, and thus has applications in many diverse fields, such as environmental biology, biotechnology, genetic engineering, and medicine. Electroporation has some advantages over other genetic transformation strategies, including the simplicity of the method, a wide range of adjustable parameters (possibility of optimization), high reproducibility and avoidance of the use of chemicals toxic to cells. Here we describe an optimized electroporation procedure for the industrially important fungus Acremonium chrysogenum, using germinated conidia and fragmented young mycelium. In both cases, the transformation efficiency was higher compared to the conventional polyethylene glycol (PEG)-mediated transformation of protoplasts.
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Eletroporação/métodos , Fungos/genética , Acremonium/genética , Biotecnologia/métodos , Engenharia Genética/métodos , Micélio/genética , Polietilenoglicóis/química , Protoplastos , Reprodutibilidade dos Testes , Transformação Genética/genéticaRESUMO
Introduction: The arrival of direct-acting oral anticoagulants (DOACs) has led to a change in the management of non-valvular atrial fibrillation (NVAF) in recent years. The objectives of this study are to determine the level of therapeutic control of anticoagulation with vitamin K antagonists (VKA) and its possible involvement in major adverse cardiovascular events (MACE) and to evaluate differences between the group on VKA with respect to the group on DOACs. Patients and methods: Prospective cohort study that included consecutive patients diagnosed with NVAF in Cardiology Consultations with a clinical follow-up of 18 months. Demographic, clinical and analytical differences between groups were analyzed, including the level of therapeutic control of anticoagulation on the VKA group and its association with MACE. Results: Overall, 273 patients were included: 46.5% on VKA, 42.5% on DOACs, 11% without antithrombotic treatment. Patients on VKA spent 62.1% of their time within therapeutic range (TTR by the Rosendaal formule). There were no differences in MACE depending on anticoagulation control. The DOACs group presented lesser MACE rate than the VKA group (13.4 vs. 4.3%; 0.90; HR 0.90; 0.83-0.98 p = 0.01) with lower cardiovascular mortality (0.0 vs. 5.5%; HR, 0.94; 0.90-0.98; p = 0.01) and total mortality (0.9 vs. 12.6%; HR, 0.88; 0.82-0.94; p < 0.01) although without significant differences in hemorrhagic (0.9 vs. 4.7 %; p = 0.07), or ischemic events (2.6 vs. 0.8%, p = 0.27). Conclusions: Patients on VKA have a different clinical profile than those who receive DOACs. Patients on VKA have an inadequate control of the anticoagulation in quite the half of the cases. The VKA group presented more MACE than the DOACs group.
Introducción: La llegada de los anticoagulantes directos (ACD) ha supuesto un cambio en el tratamiento de la fibrilación auricular no valvular (FANV) en los últimos años. Los objetivos de este estudio son determinar el grado de control de la anticoagulación con antivitamina K (AVK) y su posible implicación en efectos cardiovasculares adversos mayores (ECAM) y evaluar las diferencias entre el grupo en tratamiento con AVK respecto del grupo con ACD. Pacientes y métodos: Estudio de cohorte prospectivo que incluyó a pacientes consecutivos diagnosticados con FANV valorados en el Servicio de Cardiología con un seguimiento de 18 meses. Se analizaron diferencias demográficas, clínicas y analíticas entre grupos, incluido el grado de control de la anticoagulación del grupo AVK y su posible relación con ECAM. Resultados: Se incluyó a 273 pacientes: 46.5% tratados con AVK, 42.5% con ACD y 11% sin tratamiento anticoagulante. El control de la anticoagulación con AVK fue del 62.1%, sin diferencias en ECAM en función de control. El grupo ACD presentó menos ECAM que el grupo de AVK (13.4 vs. 4.3%; HR, 0.90; 0.83-0.98; p = 0.01), con una menor mortalidad cardiovascular (0.0 vs. 5.5%; HR, 0.94; 0.90-0.98; p = 0.01) y total (0.9 vs. 12.6%; HR, 0.88; 0.82-0.94; p < 0,01), aunque sin diferencias significativas en eventos hemorrágicos (0.9 vs. 4.7%; p = 0.07) ni isquémicos (2.6 vs. 0.8%; p = 0.27). Discusión: Los pacientes con AVK poseen un perfil clínico diferente en comparación con los que reciben ACD. El control de anticoagulación del grupo de AVK fue inadecuado en casi la mitad de los casos. El grupo de AVK presentó más ECAM que el grupo de ACD.
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Anticoagulantes/administração & dosagem , Fibrilação Atrial/tratamento farmacológico , Inibidores do Fator Xa/administração & dosagem , Vitamina K/antagonistas & inibidores , Administração Oral , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/efeitos adversos , Fibrilação Atrial/complicações , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/prevenção & controle , Estudos de Coortes , Inibidores do Fator Xa/efeitos adversos , Feminino , Seguimentos , Hemorragia/induzido quimicamente , Hemorragia/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
Resumen Introducción: La llegada de los anticoagulantes directos (ACD) ha supuesto un cambio en el tratamiento de la fibrilación auricular no valvular (FANV) en los últimos años. Los objetivos de este estudio son determinar el grado de control de la anticoagulación con antivitamina K (AVK) y su posible implicación en efectos cardiovasculares adversos mayores (ECAM) y evaluar las diferencias entre el grupo en tratamiento con AVK respecto del grupo con ACD. Pacientes y métodos: Estudio de cohorte prospectivo que incluyó a pacientes consecutivos diagnosticados con FANV valorados en el Servicio de Cardiología con un seguimiento de 18 meses. Se analizaron diferencias demográficas, clínicas y analíticas entre grupos, incluido el grado de control de la anticoagulación del grupo AVK y su posible relación con ECAM. Resultados: Se incluyó a 273 pacientes: 46.5% tratados con AVK, 42.5% con ACD y 11% sin tratamiento anticoagulante. El control de la anticoagulación con AVK fue del 62.1%, sin diferencias en ECAM en función de control. El grupo ACD presentó menos ECAM que el grupo de AVK (13.4 vs. 4.3%; HR, 0.90; 0.83-0.98; p = 0.01), con una menor mortalidad cardiovascular (0.0 vs. 5.5%; HR, 0.94; 0.90-0.98; p = 0.01) y total (0.9 vs. 12.6%; HR, 0.88; 0.82-0.94; p menor que 0,01), aunque sin diferencias significativas en eventos hemorrágicos (0.9 vs. 4.7%; p = 0.07) ni isquémicos (2.6 vs. 0.8%; p = 0.27). Discusión: Los pacientes con AVK poseen un perfil clínico diferente en comparación con los que reciben ACD. El control de anticoagulación del grupo de AVK fue inadecuado en casi la mitad de los casos. El grupo de AVK presentó más ECAM que el grupo de ACD.
Abstract Introduction: The arrival of direct-acting oral anticoagulants (DOACs) has led to a change in the management of non-valvular atrial fibrillation (NVAF) in recent years. The objectives of this study are to determine the level of therapeutic control of anticoagulation with vitamin K antagonists (VKA) and its possible involvement in major adverse cardiovascular events (MACE) and to evaluate differences between the group on VKA with respect to the group on DOACs. Patients and methods: Prospective cohort study that included consecutive patients diagnosed with NVAF in Cardiology Consultations with a clinical follow-up of 18 months. Demographic, clinical and analytical differences between groups were analyzed, including the level of therapeutic control of anticoagulation on the VKA group and its association with MACE. Results: Overall, 273 patients were included: 46.5% on VKA, 42.5% on DOACs, 11% without antithrombotic treatment. Patients on VKA spent 62.1% of their time within therapeutic range (TTR by the Rosendaal formule). There were no differences in MACE depending on anticoagulation control. The DOACs group presented lesser MACE rate than the VKA group (13.4 vs. 4.3%; 0.90; HR 0.90; 0.83-0.98 p = 0.01) with lower cardiovascular mortality (0.0 vs. 5.5%; HR, 0.94; 0.90-0.98; p = 0.01) and total mortality (0.9 vs. 12.6%; HR, 0.88; 0.82-0.94; p less 0.01) although without significant differences in hemorrhagic (0.9 vs. 4.7 %; p = 0.07), or ischemic events (2.6 vs. 0.8%, p = 0.27). Conclusions: Patients on VKA have a different clinical profile than those who receive DOACs. Patients on VKA have an inadequate control of the anticoagulation in quite the half of the cases. The VKA group presented more MACE than the DOACs group.
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Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Fibrilação Atrial/tratamento farmacológico , Vitamina K/antagonistas & inibidores , Inibidores do Fator Xa/administração & dosagem , Anticoagulantes/administração & dosagem , Fibrilação Atrial/complicações , Doenças Cardiovasculares/epidemiologia , Administração Oral , Estudos Prospectivos , Estudos de Coortes , Seguimentos , Inibidores do Fator Xa/efeitos adversos , Hemorragia/induzido quimicamente , Hemorragia/epidemiologia , Anticoagulantes/efeitos adversosRESUMO
Three different transformation strategies were tested and compared in an attempt to facilitate and improve the genetic transformation of Acremonium chrysogenum, the exclusive producer of the pharmaceutically relevant ß-lactam antibiotic cephalosporin C. We investigated the use of high-voltage electric pulse to transform germinated conidia and young mycelium and compared these procedures with traditional PEG-mediated protoplast transformation, using phleomycin resistance as selection marker in all cases. The effect of the field strength and capacitance on transformation frequency and cell viability was evaluated. The electroporation of germinated conidia and young mycelium was found to be appropriate for transforming A. chrysogenum with higher transformation efficiencies than those obtained with the conventional protoplast-based transformation procedures. The developed electroporation strategy is fast, simple to perform, and highly reproducible and avoids the use of chemicals toxic to cells. Electroporation of young mycelium represents an alternative method for transformation of fungal strains with reduced or no sporulation, as often occurs in laboratory-developed strains in the search for high-yielding mutants for industrial bioprocesses.
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Acremonium/genética , Eletroporação/métodos , Transformação Genética , Acremonium/efeitos dos fármacos , Acremonium/metabolismo , Cefalosporinas/biossíntese , Farmacorresistência Bacteriana , Viabilidade Microbiana , Micélio/efeitos dos fármacos , Micélio/genética , Micélio/metabolismo , Fleomicinas/farmacologia , Protoplastos/fisiologia , Esporos Fúngicos/efeitos dos fármacos , Esporos Fúngicos/genética , Esporos Fúngicos/metabolismoRESUMO
During evolution, some homologs proteins appear with different connectivity between secondary structures (different topology) but conserving the tridimensional arrangement of them (same architecture). These events can produce two types of arrangements; circular permutation or non-cyclic permutations. The first one results in the N and C terminus transferring to a different position on a protein sequence while the second refers to a more complex arrangement of the structural elements. In ribokinase superfamily, two different topologies can be identified, which are related to each other as a non-cyclic permutation occurred during the evolution. Interestingly, this change in topology is correlated with the nucleotide specificity of its members. Thereby, the connectivity of the secondary elements allows us to distinguish an ATP-dependent and an ADP-dependent topology. Here we address the impact of introducing the topology of a homologous ATP-dependent kinase in an ADP-dependent kinase (Thermococcus litoralis glucokinase) in the structure, nucleotide specificity, and substrate binding order of the engineered enzyme. Structural evidence demonstrates that rewiring the topology of TlGK leads to an active and soluble enzyme without modifications on its three-dimensional architecture. The permuted enzyme (PerGK) retains the nucleotide preference of the parent TlGK enzyme but shows a change in the substrate binding order. Our results illustrate how the rearrangement of the protein folding topology during the evolution of the ribokinase superfamily enzymes may have dictated the substrate-binding order in homologous enzymes of this superfamily.
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Proteínas Arqueais/química , Proteínas Arqueais/metabolismo , Glucoquinase/química , Glucoquinase/metabolismo , Estrutura Secundária de Proteína , Thermococcus/enzimologia , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Dicroísmo Circular , Cristalografia por Raios X , Cinética , Fosfotransferases (Aceptor do Grupo Álcool)/química , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Ligação Proteica , Dobramento de Proteína , Espalhamento a Baixo Ângulo , Especificidade por Substrato , Difração de Raios XRESUMO
Bioremediation of polycyclic aromatic hydrocarbons (PAHs)-contaminated soils through the biostimulation and bioaugmentation processes can be a strategy for the clean-up of oil spills and environmental accidents. In this work, an induced microbial selection method using PAH-polluted soils was successfully used to construct two microbial consortia exhibiting high degradation levels of low and high molecular weight PAHs. Six fungal and seven bacterial native strains were used to construct mixed consortia with the ability to tolerate high amounts of phenanthrene (Phe), pyrene (Pyr) and benzo(a)pyrene (BaP) and utilize these compounds as a sole carbon source. In addition, we used two engineered PAH-degrading fungal strains producing heterologous ligninolytic enzymes. After a previous selection using microbial antagonism tests, the selection was performed in microcosm systems and monitored using PCR-DGGE, CO2 evolution and PAH quantitation. The resulting consortia (i.e., C1 and C2) were able to degrade up to 92% of Phe, 64% of Pyr and 65% of BaP out of 1000 mg kg-1 of a mixture of Phe, Pyr and BaP (1:1:1) after a two-week incubation. The results indicate that constructed microbial consortia have high potential for soil bioremediation by bioaugmentation and biostimulation and may be effective for the treatment of sites polluted with PAHs due to their elevated tolerance to aromatic compounds, their capacity to utilize them as energy source.
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Consórcios Microbianos , Poluição por Petróleo/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Microbiologia do Solo , Poluentes do Solo/análise , Solo/química , Bactérias/metabolismo , Biodegradação Ambiental , Fungos/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Poluentes do Solo/metabolismoRESUMO
The mutant Penicillium chrysogenum strain dogR5, derived from strain AS-P-78, does not respond to glucose regulation of penicillin biosynthesis and ß-galactosidase, and is partially deficient in D-glucose phosphorilating activity. We have transformed strain dogR5 with the (hexokinase) hxk2 gene from Saccharomyces cerevisiae. Transformants recovered glucose control of penicillin biosynthesis in different degrees, and acquired a hexokinase (fructose phosphorylating) activity absent in strains AS- P-78 and dogR5. Interestingly, they also recovered glucose regulation of ß-galactosidase. On the other hand, glucokinase activity was affected in different ways in the transformants; one of which showed a lower activity than the parental dogR5, but normal glucose regulation of penicillin biosynthesis. Our results show that Penicillium chrysogenum AS-P-78 and dogR5 strains lack hexokinase, and suggest that an enzyme with glucokinase activity is involved in glucose regulation of penicillin biosynthesis and ß-galactosidase, thus signaling glucose in both primary and secondary metabolism; however, catalytic and signaling activities seem to be independent.
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Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Hexoquinase/metabolismo , Penicilinas/biossíntese , Penicillium chrysogenum/genética , Penicillium chrysogenum/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Hexoquinase/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Transformação Genética , beta-Galactosidase/biossínteseRESUMO
The mutant Penicillium chrysogenum strain dogR5, derived from strain AS-P-78, does not respond to glucose regulation of penicillin biosynthesis and β-galactosidase, and is partially deficient in D-glucose phosphorilating activity. We have transformed strain dogR5 with the (hexokinase) hxk2 gene from Saccharomyces cerevisiae. Transformants recovered glucose control of penicillin biosynthesis in different degrees, and acquired a hexokinase (fructose phosphorylating) activity absent in strains AS- P-78 and dogR5. Interestingly, they also recovered glucose regulation of β-galactosidase. On the other hand, glucokinase activity was affected in different ways in the transformants; one of which showed a lower activity than the parental dogR5, but normal glucose regulation of penicillin biosynthesis. Our results show that Penicillium chrysogenum AS-P-78 and dogR5 strains lack hexokinase, and suggest that an enzyme with glucokinase activity is involved in glucose regulation of penicillin biosynthesis and β-galactosidase, thus signaling glucose in both primary and secondary metabolism; however, catalytic and signaling activities seem to be independent.
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Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Hexoquinase/metabolismo , Penicilinas/biossíntese , Penicillium chrysogenum/genética , Penicillium chrysogenum/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Hexoquinase/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Transformação Genética , beta-Galactosidase/biossínteseRESUMO
The mutant Penicillium chrysogenum strain dogR5, derived from strain AS-P-78, does not respond to glucose regulation of penicillin biosynthesis and β-galactosidase, and is partially deficient in D-glucose phosphorilating activity. We have transformed strain dogR5 with the (hexokinase) hxk2 gene from Saccharomyces cerevisiae. Transformants recovered glucose control of penicillin biosynthesis in different degrees, and acquired a hexokinase (fructose phosphorylating) activity absent in strains AS- P-78 and dogR5. Interestingly, they also recovered glucose regulation of β-galactosidase. On the other hand, glucokinase activity was affected in different ways in the transformants; one of which showed a lower activity than the parental dogR5, but normal glucose regulation of penicillin biosynthesis. Our results show that Penicillium chrysogenum AS-P-78 and dogR5 strains lack hexokinase, and suggest that an enzyme with glucokinase activity is involved in glucose regulation of penicillin biosynthesis and β-galactosidase, thus signaling glucose in both primary and secondary metabolism; however, catalytic and signaling activities seem to be independent.
Assuntos
Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Hexoquinase/metabolismo , Penicilinas/biossíntese , Penicillium chrysogenum/genética , Penicillium chrysogenum/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Hexoquinase/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Transformação Genética , beta-Galactosidase/biossínteseRESUMO
Nine native non-ligninolytic fungal strains were isolated from Maya crude oil-contaminated soil and selected based on their ability to grow and use crude oil and several polycyclic aromatic hydrocarbons (PAHs) as carbon source, for their application to PAH removal in soil. The fungi were identified by PCR amplification of intergenic transcribed sequences regions and microbiological techniques, and results showed them to be part of the genera Fusarium, Neurospora, Aspergillus, Scedosporium, Penicillium, Neosartorya and Talaromyces. A primary selection of fungi was made in minimal medium plates, considering the tolerance to different concentrations of PAHs for each strain. The radial extension rate exhibited significant differences (p < 0.05) from 200 to 1,000 mg of PAHs mixture l⻹. A secondary selection of Aspergillus terreus, Talaromyces spectabilis, and Fusarium sp. was achieved based on their tolerance to 2,000 mg of a mixture of Phenanathrene and Pyrene kg⻹ of soil in a solid-state microcosm system for 2 weeks. The percentage of PAH removal obtained by the three strains was approximately 21 % of the mixture.
Assuntos
Fungos/isolamento & purificação , Fungos/metabolismo , Petróleo/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Biotransformação , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Fungos/classificação , Fungos/genética , Técnicas de Tipagem Micológica , Filogenia , Análise de Sequência de DNARESUMO
ADP-dependent glucokinases represent a unique family of kinases that belong to the ribokinase superfamily, being present mainly in hyperthermophilic archaea. For these enzymes there is no agreement about the magnitude of the structural transitions associated with ligand binding and whether they are meaningful to the function of the enzyme. We used the ADP-dependent glucokinase from Thermococcus litoralis as a model to investigate the conformational changes observed in X-ray crystallographic structures upon substrate binding and to compare them with those determined in solution in order to understand their interplay with the glucokinase function. Initial velocity studies indicate that catalysis follows a sequential ordered mechanism that correlates with the structural transitions experienced by the enzyme in solution and in the crystal state. The combined data allowed us to resolve the open-closed conformational transition that accounts for the complete reaction cycle and to identify the corresponding clusters of aminoacids residues responsible for it. These results provide molecular bases for a general mechanism conserved across the ADP-dependent kinase family.
Assuntos
Proteínas Arqueais/química , Glucoquinase/química , Conformação Proteica , Thermococcus/enzimologia , Trifosfato de Adenosina/química , Trifosfato de Adenosina/metabolismo , Sequência de Aminoácidos , Proteínas Arqueais/genética , Proteínas Arqueais/metabolismo , Sítios de Ligação/genética , Biocatálise , Cristalografia por Raios X , Glucoquinase/classificação , Glucoquinase/metabolismo , Glucose/química , Glucose/metabolismo , Temperatura Alta , Cinética , Modelos Moleculares , Dados de Sequência Molecular , Filogenia , Ligação Proteica , Estrutura Terciária de Proteína , Espalhamento a Baixo Ângulo , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Thermococcus/genética , Difração de Raios XRESUMO
Yersinia enterocolitica has been isolated from a batch of pork-derived products, from healthy and diseased animals, and from different types of milk and dairy products, among others. We studied the prevalence and diversity of Y. enterocolitica isolated from raw cow's milk collected from stables in Mexico City. Of the 1,300 samples analyzed, Y. enterocolitica was isolated in 454, with an average of 25% positive samples for each stable. Of the total isolated bacteria of the Yersinia genus, 44.25% were Y. enterocolitica, 18.28% were Y. kristensenii, 13.65% were Y. intermedia, 14.85% were Y. frederiksenii, and 9.14% were Y. aldovae. Among the different strains of Y. enterocolitica, biotype 1A was present in 70%, biotype 2 in 13.2%, biotype 3 in 8.54%, and biotype 4 in 8.15% of samples. Serotypes O:5, O:3, O:2, and O:9 were found in all biotypes identified. There were no statistically significant differences in the isolation of this bacterium with respect to the stables where they were found, although there was significant difference regarding the time of year. The data obtained in this work show the need to protect public health in Mexico against infections transmitted by raw cow's milk.