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1.
J Eur Soc Policy ; 33(1): 101-116, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38603310

RESUMO

Using a static microsimulation model based on a link between survey and administrative data, this article investigates the effects of the pandemic on income distribution in Italy in 2020. The analysis focuses on both individuals and households by simulating through nowcasting techniques changes in labour income and in equivalized income, respectively. For both units of observations, we compare changes before and after social policy interventions, that is, automatic stabilizers and benefits introduced by the government to address the effects of the COVID-19 emergency. We find that the pandemic has led to a relatively greater drop in labour income for those lying in the poorest quantiles, which, however, benefited more from the income support benefits. As a result, compared with the 'No-COVID scenario', income poverty and inequality indices grow considerably when these benefits are not considered, whereas the poverty increase greatly narrows and inequality slightly decreases once social policy interventions are taken into account. This evidence signals the crucial role played by cash social transfers to contrast with the most serious economic consequences of the pandemic.

2.
Int J Mol Sci ; 23(6)2022 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-35328363

RESUMO

Arsenic (As) pollution is a widespread problem worldwide. In recent years, biosensors based on enzymatic inhibition have been developed for arsenic detection, making the study of the effect of inhibitors on the selected enzymatic activity crucial for their setup. The arsenate reductase of Thermus thermophilus HB27, TtArsC, reduces As(V) into As(III), but is also endowed with phosphatase activity. This work investigates the inhibitory effects of As(V) and As(III) on phosphatase activity by taking advantage of a simple colorimetric assay; the results show that both of them are non-competitive inhibitors affecting the Vmax but not the KM of the reaction. However, their Ki values are different from each other (15.2 ± 1.6 µM for As(V) and 394.4 ± 40.3 µm with As(III)), indicating a higher inhibitory effect by As(V). Moreover, the inhibition-based biosystem results to be selective for As(V) since several other metal ions and salts do not affect TtArsC phosphatase activity; it exhibits a sensitivity of 0.53 ± 0.03 mU/mg/µM and a limit of detection (LOD) of 0.28 ± 0.02 µM. The good sensitivity and specificity for As(V) point to consider inhibition of TtArsC phosphatase activity for the setup of a novel biosensor for the detection of As(V).


Assuntos
Arsênio , Técnicas Biossensoriais , Arseniato Redutases , Monoéster Fosfórico Hidrolases , Thermus thermophilus
3.
Int J Mol Sci ; 24(1)2022 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-36613686

RESUMO

In the bio-based era, cellulolytic and hemicellulolytic enzymes are biocatalysts used in many industrial processes, playing a key role in the conversion of recalcitrant lignocellulosic waste biomasses. In this context, many thermophilic microorganisms are considered as convenient sources of carbohydrate-active enzymes (CAZymes). In this work, a functional genomic annotation of Alicyclobacillus mali FL18, a recently discovered thermo-acidophilic microorganism, showed a wide reservoir of putative CAZymes. Among them, a novel enzyme belonging to the family 9 of glycosyl hydrolases (GHs), named AmCel9, was identified; in-depth in silico analyses highlighted that AmCel9 shares general features with other GH9 members. The synthetic gene was expressed in Escherichia coli and the recombinant protein was purified and characterized. The monomeric enzyme has an optimal catalytic activity at pH 6.0 and has comparable activity at temperatures ranging from 40 °C to 70 °C. It also has a broad substrate specificity, a typical behavior of multifunctional cellulases; the best activity is displayed on ß-1,4 linked glucans. Very interestingly, AmCel9 also hydrolyses filter paper and microcrystalline cellulose. This work gives new insights into the properties of a new thermophilic multifunctional GH9 enzyme, that looks a promising biocatalyst for the deconstruction of lignocellulose.


Assuntos
Alicyclobacillus , Celulases , Enzimas Multifuncionais , Glucanos/metabolismo , Alicyclobacillus/genética , Alicyclobacillus/metabolismo , Celulases/metabolismo
4.
Aesthet Surg J ; 39(2): 164-173, 2019 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-29579138

RESUMO

Background: Breast shape is defined utilizing mainly qualitative assessment (full, flat, ptotic) or estimates, such as volume or distances between reference points, that cannot describe it reliably. Objectives: The authors quantitatively described breast shape with two parameters derived from a statistical methodology denominated by principal component analysis (PCA). Methods: The authors created a heterogeneous dataset of breast shapes acquired with a commercial infrared 3-dimensional scanner on which PCA was performed. The authors plotted on a Cartesian plane the two highest values of PCA for each breast (principal components 1 and 2). Testing of the methodology on a preoperative and posttreatment surgical case and test-retest was performed by two operators. Results: The first two principal components derived from PCA characterize the shape of the breast included in the dataset. The test-retest demonstrated that different operators obtain very similar values of PCA. The system is also able to identify major changes in the preoperative and posttreatment stages of a two-stage reconstruction. Even minor changes were correctly detected by the system. Conclusions: This methodology can reliably describe the shape of a breast. An expert operator and a newly trained operator can reach similar results in a test/re-testing validation. Once developed and after further validation, this methodology could be employed as a good tool for outcome evaluation, auditing, and benchmarking.


Assuntos
Neoplasias da Mama/cirurgia , Mama/diagnóstico por imagem , Imageamento Tridimensional/métodos , Mamoplastia/normas , Mastectomia/efeitos adversos , Adulto , Idoso , Pontos de Referência Anatômicos/anatomia & histologia , Pontos de Referência Anatômicos/diagnóstico por imagem , Benchmarking/métodos , Mama/anatomia & histologia , Mama/cirurgia , Feminino , Humanos , Imageamento Tridimensional/instrumentação , Raios Infravermelhos , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde/métodos , Análise de Componente Principal , Smartphone , Adulto Jovem
5.
Microb Cell Fact ; 17(1): 78, 2018 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-29776370

RESUMO

BACKGROUND: The characterization of the molecular determinants of metal resistance has potential biotechnological application in biosensing and bioremediation. In this context, the bacterium Thermus thermophilus HB27 is a metal tolerant thermophile containing a set of genes involved in arsenic resistance which, differently from other microbes, are not organized into a single operon. They encode the proteins: arsenate reductase, TtArsC, arsenic efflux membrane transporter, TtArsX, and transcriptional repressor, TtSmtB. RESULTS: In this work we show that the arsenic efflux protein TtArsX and the arsenic responsive transcriptional repressor TtSmtB are required to provide resistance to cadmium. We analyzed the sensitivity to Cd(II) of mutants lacking TtArsX, finding that they are more sensitive to this metal than the wild type strain. In addition, using promoter probe reporter plasmids, we show that the transcription of TtarsX is also stimulated by the presence of Cd(II) in a TtSmtB-dependent way. Actually, a regulatory circuit composed of TtSmtB and a reporter gene expressed from the TtarsX promoter responds to variation in Cd(II), As(III) and As(V) concentrations. CONCLUSIONS: Our results demonstrate that the system composed by TtSmtB and TtArsX is responsible for both the arsenic and cadmium resistance in T. thermophilus. The data also support the use of T. thermophilus as a suitable chassis for the design and development of As-Cd biosensors.


Assuntos
Arsênio/química , Proteínas de Bactérias/metabolismo , Cádmio/química , Thermus thermophilus/genética
6.
J Pept Sci ; 24(7): e3095, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29900637

RESUMO

Bioactive peptides derived from the receptor-binding region of human apolipoprotein E have previously been reported. All these peptides, encompassing fragments of this region or designed on the basis of short repeated cationic sequences identified in the same region, show toxic activities against a broad spectrum of bacteria and interesting immunomodulatory effects. However, the ability of these molecules to exert antibiofilm properties has not been described so far. In the present work, we report the characterization of a novel peptide, corresponding to residues 133 to 167 of human apolipoprotein E, here named ApoE (133-167). This peptide, besides presenting interesting properties comparable with those reported for other ApoE-derived peptides, such as a direct killing activity against a broad spectrum of bacteria or the ability to downregulate lipopolysaccharide-induced cytokine release, is also endowed with significant antibiofilm properties. Indeed, the peptide is able to strongly affect the formation of the extracellular matrix and also the viability of encapsulated bacteria. Noteworthy, ApoE (133-167) is not toxic toward human and murine cell lines and is able to assume ordered conformations in the presence of membrane mimicking agents. Taken together, collected evidences about biological and structural properties of ApoE (133-167) open new perspectives in the design of therapeutic agents based on human-derived bioactive peptides.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Apolipoproteínas E/química , Bactérias/efeitos dos fármacos , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/farmacologia , Animais , Apolipoproteínas E/farmacologia , Bactérias/crescimento & desenvolvimento , Biofilmes/efeitos dos fármacos , Células Cultivadas , Citocinas/antagonistas & inibidores , Citocinas/biossíntese , Relação Dose-Resposta a Droga , Humanos , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Camundongos , Testes de Sensibilidade Microbiana , Células RAW 264.7 , Relação Estrutura-Atividade
7.
Sci Rep ; 13(1): 15912, 2023 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-37741863

RESUMO

We disentangle the channels through which Covid-19 has affected the performance of university students by setting up an econometric strategy to identify separately changes in both teaching and evaluation modes, and the short and long term effects of mobility restrictions. We exploit full and detailed information from the administrative archives of one among the first universities to be shut down since the virus spread from Wuhan. The results help solving the inconsistencies in the literature by providing evidence of a composite picture where negative effects such as those caused by the sudden shift to remote learning and by the exposure to mobility restrictions, overlap to opposite effects due to a change in evaluation methods and home confinement during the exam's preparation. Such overlap of conflicting effects, weakening the signaling role of tertiary education, would add to the learning loss by further exacerbating future consequences on the "Covid" generation.


Assuntos
COVID-19 , Humanos , Estudantes , Escolaridade , Aprendizagem , Transdução de Sinais
8.
Antioxidants (Basel) ; 12(3)2023 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-36979012

RESUMO

The aim of this work was to exploit the antioxidant potential of molecules recovered during the pectin purification process of citrus lemon waste and to encapsulate them in stable pectin films, with a view to a green and circular economy process. Antioxidant molecules were recovered during the pectin purification process, further recovering matter from the waste. Seven molecules were identified and quantified, and the antioxidant power of the mixture and its stability over time was evaluated. To improve the stability of the bioactive fraction, this was complexed with 2-hydroxypropyl-ß-cyclodextrin (HP-ß-CD); indeed, this procedure increased their thermal stability from 120 °C up to 250 °C, as verified by thermogravimetry. Furthermore, the most promising complexes were studied under autoclave-like conditions (120 °C, 28 min) to simulate thermal sterilization. The antioxidants and HP-ß-CD were combined in a pectin film, showing increased stability over time (up to three times) compared to uncomplexed antioxidants. This process represents a first step towards the development of applicable devices for the delivery of antioxidant molecules.

9.
Biomed J ; 46(1): 93-99, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36038109

RESUMO

BACKGROUND: At the end of 2019 a new respiratory syndrome emerged in China named Coronavirus disease 2019 (COVID-19) due to SARS-CoV-2 infection. Considering the severity of the disease in adult subjects with one or more chronic pathologies, it was mandatory to find simple and effective biomarkers for negative prognosis of the disease easily available at the admission to the hospital. METHODS: To identify possible parameters showing association with the outcome in COVID-19 patients with pre-existing chronic diseases, blood biochemical profiles of 511 patients, enrolled from March to June 2020, were retrospectively evaluated. The pathological conditions taken into consideration were diabetes, arterial hypertension, chronic kidney disease, cardiovascular diseases, chronic obstructive pulmonary disease, obesity, and cancer. All the data were collected upon admission to the emergency room (ER) during the indicated period. RESULTS: We observed that serum and ionized calcium were prevalently altered in our cohort. We determined that hypocalcemia was a major parameter associated with mechanical ventilation and poor prognosis, correlating also with the presence of comorbidities such as cardiovascular diseases, chronic kidney disease, and cancer. In addition, we found a positive correlation between hypocalcemia and clinical complications during hospitalizations. CONCLUSIONS: Our results strengthen the relevance of serum calcium concentration as a useful prognostic biomarker in hospitalized COVID-19 patients.


Assuntos
COVID-19 , Doenças Cardiovasculares , Hipocalcemia , Adulto , Humanos , SARS-CoV-2 , Estudos Retrospectivos , Hipocalcemia/diagnóstico , Cálcio , Biomarcadores
10.
Clin Pract ; 13(4): 924-943, 2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37623266

RESUMO

BACKGROUND: The aging process starts in the center of the face, in the periocular region and around the mouth, with a combination of volume loss, tissue descent, deepened wrinkles, and the loss of skin structure and quality. Recently, several studies have demonstrated the efficacy of therapies based on autologous adipose tissue grafting, which leverages the properties of stromal vascular fraction (SVF) and adipose-derived mesenchymal stem cells (ADSCs) to accelerate the regenerative processes of the skin. This study aims to verify the ability of guided superficial enhanced fluid fat injection (SEFFI) in the facial area to correct volume loss and skin aging, proving that this standardized procedure has a very low rate of complications. METHODS: We retrospectively collected data from 2365 procedures performed in Italian centers between 2019 and 2021. Guided SEFFI was performed alone or combined with cosmetic treatments, including the use of hyaluronic acid filler, suspension threads, synthetic calcium hydroxylapatite, botulin toxin, and microneedling. RESULTS: guided SEFFI was used alone in more than 60% of the patients and in all facial areas. In about one-tenth of the patients, guided SEFFI was combined with a botulin toxin treatment or hyaluronic acid filling. Other procedures were used more rarely. Ecchymosis in the donor or injection sites was the most frequent adverse event but was only observed in 14.2% and 38.6% of the patients, respectively. CONCLUSIONS: The guided SEFFI technique is standardized and minimally invasive, leading to very few complications. It constitutes a promising antiaging medical treatment that combines effectiveness, safety, and simplicity.

11.
J Popul Econ ; 34(1): 303-360, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32952308

RESUMO

In the current context of the COVID-19 pandemic, working from home (WFH) became of great importance for a large share of employees since it represents the only option to both continue working and minimise the risk of virus exposure. Uncertainty about the duration of the pandemic and future contagion waves even led companies to view WFH as a 'new normal' way of working. Based on influence function regression methods, this paper explores the potential consequences in the labour income distribution related to a long-lasting increase in WFH feasibility among Italian employees. Results show that a positive shift in WFH feasibility would be associated with an increase in average labour income, but this potential benefit would not be equally distributed among employees. Specifically, an increase in the opportunity to WFH would favour male, older, high-educated, and high-paid employees. However, this 'forced innovation' would benefit more employees living in provinces have been more affected by the novel coronavirus. WFH thus risks exacerbating pre-existing inequalities in the labour market, especially if it will not be adequately regulated. As a consequence, this study suggests that policies aimed at alleviating inequality, like income support measures (in the short run) and human capital interventions (in the long run), should play a more important compensating role in the future.

12.
J Popul Econ ; 34(1): 275-301, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32868965

RESUMO

Identifying structural breaks in the dynamics of COVID-19 contagion is crucial to promptly assess policies and evaluate the effectiveness of lockdown measures. However, official data record infections after a critical and unpredictable delay. Moreover, people react to the health risks of the virus and also anticipate lockdowns. All of this makes it complex to quickly and accurately detect changing patterns in the virus's infection dynamic. We propose a machine learning procedure to identify structural breaks in the time series of COVID-19 cases. We consider the case of Italy, an early-affected country that was unprepared for the situation, and detect the dates of structural breaks induced by three national lockdowns so as to evaluate their effects and identify some related policy issues. The strong but significantly delayed effect of the first lockdown suggests a relevant announcement effect. In contrast, the last lockdown had significantly less impact. The proposed methodology is robust as a real-time procedure for early detection of the structural breaks: the impact of the first two lockdowns could have been correctly identified just the day after they actually occurred.

13.
Artigo em Inglês | MEDLINE | ID: mdl-34069056

RESUMO

Extremophiles are microorganisms that populate habitats considered inhospitable from an anthropocentric point of view and are able to tolerate harsh conditions such as high temperatures, extreme pHs, high concentrations of salts, toxic organic substances, and/or heavy metals. These microorganisms have been broadly studied in the last 30 years and represent precious sources of biomolecules and bioprocesses for many biotechnological applications; in this context, scientific efforts have been focused on the employment of extremophilic microbes and their metabolic pathways to develop biomonitoring and bioremediation strategies to face environmental pollution, as well as to improve biorefineries for the conversion of biomasses into various chemical compounds. This review gives an overview on the peculiar metabolic features of certain extremophilic microorganisms, with a main focus on thermophiles, which make them attractive for biotechnological applications in the field of environmental remediation; moreover, it sheds light on updated genetic systems (also those based on the CRISPR-Cas tool), which expand the potentialities of these microorganisms to be genetically manipulated for various biotechnological purposes.


Assuntos
Extremófilos , Metais Pesados , Biodegradação Ambiental , Ecossistema , Extremófilos/genética , Redes e Vias Metabólicas
14.
Sci Rep ; 11(1): 2991, 2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33542380

RESUMO

The correct immobilization and orientation of enzymes on nanosurfaces is a crucial step either for the realization of biosensors, as well as to guarantee the efficacy of the developed biomaterials. In this work we produced two versions of a chimeric protein, namely ArsC-Vmh2 and Vmh2-ArsC, which combined the self-assembling properties of Vmh2, a hydrophobin from Pleurotus ostreatus, with that of TtArsC, a thermophilic arsenate reductase from Thermus thermophilus; both chimeras were heterologously expressed in Escherichia coli and purified from inclusion bodies. They were characterized for their enzymatic capability to reduce As(V) into As(III), as well as for their immobilization properties on polystyrene and gold in comparison to the native TtArsC. The chimeric proteins immobilized on polystyrene can be reused up to three times and stored for 15 days with 50% of activity loss. Immobilization on gold electrodes showed that both chimeras follow a classic Langmuir isotherm model towards As(III) recognition, with an association constant (KAsIII) between As(III) and the immobilized enzyme, equal to 650 (± 100) L mol-1 for ArsC-Vmh2 and to 1200 (± 300) L mol-1 for Vmh2-ArsC. The results demonstrate that gold-immobilized ArsC-Vmh2 and Vmh2-ArsC can be exploited as electrochemical biosensors to detect As(III).


Assuntos
Arseniato Redutases/química , Arsênio/isolamento & purificação , Técnicas Biossensoriais , Proteínas Fúngicas/química , Proteínas Recombinantes de Fusão/química , Arsênio/toxicidade , Enzimas Imobilizadas/química , Escherichia coli/genética , Humanos , Pleurotus/química , Pleurotus/enzimologia , Thermus thermophilus/enzimologia
15.
J Clin Med ; 10(5)2021 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-33801207

RESUMO

Patients in intensive care units (ICUs) were at higher risk of worsen prognosis and mortality. Here, we aimed to evaluate the ability of the Simplified Acute Physiology Score (SAPS II) to predict the risk of 7-day mortality, and to test a machine learning algorithm which combines the SAPS II with additional patients' characteristics at ICU admission. We used data from the "Italian Nosocomial Infections Surveillance in Intensive Care Units" network. Support Vector Machines (SVM) algorithm was used to classify 3782 patients according to sex, patient's origin, type of ICU admission, non-surgical treatment for acute coronary disease, surgical intervention, SAPS II, presence of invasive devices, trauma, impaired immunity, antibiotic therapy and onset of HAI. The accuracy of SAPS II for predicting patients who died from those who did not was 69.3%, with an Area Under the Curve (AUC) of 0.678. Using the SVM algorithm, instead, we achieved an accuracy of 83.5% and AUC of 0.896. Notably, SAPS II was the variable that weighted more on the model and its removal resulted in an AUC of 0.653 and an accuracy of 68.4%. Overall, these findings suggest the present SVM model as a useful tool to early predict patients at higher risk of death at ICU admission.

16.
J Vis Exp ; (178)2021 12 30.
Artigo em Inglês | MEDLINE | ID: mdl-35037656

RESUMO

Geothermal springs are rich in various metal ions due to the interaction between rock and water that takes place in the deep aquifer. Moreover, due to seasonality variation in pH and temperature, fluctuation in element composition is periodically observed within these extreme environments, influencing the environmental microbial communities. Extremophilic microorganisms that thrive in volcanic thermal vents have developed resistance mechanisms to handle several metal ions present in the environment, thus taking part to complex metal biogeochemical cycles. Moreover, extremophiles and their products have found an extensive foothold in the market, and this holds true especially for their enzymes. In this context, their characterization is functional to the development of biosystems and bioprocesses for environmental monitoring and bioremediation. To date, the isolation and cultivation under laboratory conditions of extremophilic microorganisms still represent a bottleneck for fully exploiting their biotechnological potential. This work describes a streamlined protocol for the isolation of thermophilic microorganisms from hot springs as well as their genotypical and phenotypical identification through the following steps: (1) Sampling of microorganisms from geothermal sites ("Pisciarelli", a volcanic area of Campi Flegrei in Naples, Italy); (2) Isolation of heavy metal resistant microorganisms; (3) Identification of microbial isolates; (4) Phenotypical characterization of the isolates. The methodologies described in this work might be generally applied also for the isolation of microorganisms from other extreme environments.


Assuntos
Extremófilos , Metais Pesados , Microbiota , Biodegradação Ambiental , Bioprospecção
17.
mBio ; 12(6): e0281321, 2021 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-34872358

RESUMO

Arsenic detoxification systems can be found in a wide range of organisms, from bacteria to humans. In a previous study, we discovered an arsenic-responsive transcriptional regulator in the thermophilic bacterium Thermus thermophilus HB27 (TtSmtB). Here, we characterize the arsenic resistance system of T. thermophilus in more detail. We employed TtSmtB-based pulldown assays with protein extracts from cultures treated with arsenate and arsenite to obtain an S-adenosyl-l-methionine (SAM)-dependent arsenite methyltransferase (TtArsM). In vivo and in vitro analyses were performed to shed light on this new component of the arsenic resistance network and its peculiar catalytic mechanism. Heterologous expression of TtarsM in Escherichia coli resulted in arsenite detoxification at mesophilic temperatures. Although TtArsM does not contain a canonical arsenite binding site, the purified protein does catalyze SAM-dependent arsenite methylation with formation of monomethylarsenites (MMAs) and dimethylarsenites (DMAs). In addition, in vitro analyses confirmed the unique interaction between TtArsM and TtSmtB. Next, a highly efficient ThermoCas9-based genome-editing tool was developed to delete the TtArsM-encoding gene on the T. thermophilus genome and to confirm its involvement in the arsenite detoxification system. Finally, the TtarsX efflux pump gene in the T. thermophilus ΔTtarsM genome was substituted by a gene encoding a stabilized yellow fluorescent protein (sYFP) to create a sensitive genome-based bioreporter system for the detection of arsenic ions. IMPORTANCE We here describe the discovery of an unknown protein by using a proteomics approach with a transcriptional regulator as bait. Remarkably, we successfully obtained a novel type of enzyme through the interaction with a transcriptional regulator controlling the expression of this enzyme. Employing this strategy, we isolated TtArsM, the first thermophilic prokaryotic arsenite methyltransferase, as a new enzyme of the arsenic resistance mechanism in T. thermophilus HB27. The atypical arsenite binding site of TtArsM categorizes the enzyme as the first member of a new arsenite methyltransferase type, exclusively present in the Thermus genus. The enzyme methylates arsenite-producing MMAs and DMAs. Furthermore, we developed an hyperthermophilic Cas9-based genome-editing tool, active up to 65°C. The tool allowed us to perform highly efficient, marker-free modifications (either gene deletion or insertion) in the T. thermophilus genome. With these modifications, we confirmed the critical role of TtArsM in the arsenite detoxification system and developed a sensitive whole-cell bioreporter for arsenic ions. We anticipate that the developed tool can be easily adapted for editing the genomes of other thermophilic bacteria, significantly boosting fundamental and metabolic engineering in hyperthermophilic microorganisms.


Assuntos
Arsênio/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Metiltransferases/química , Metiltransferases/genética , Thermus thermophilus/enzimologia , Sequência de Aminoácidos , Arsênio/química , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Sistemas CRISPR-Cas , Estabilidade Enzimática , Edição de Genes , Metiltransferases/metabolismo , Alinhamento de Sequência , Thermus thermophilus/química , Thermus thermophilus/genética
18.
Front Microbiol ; 12: 639697, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33897644

RESUMO

Extreme environments are excellent places to find microorganisms capable of tolerating extreme temperature, pH, salinity pressure, and elevated concentration of heavy metals and other toxic compounds. In the last decades, extremophilic microorganisms have been extensively studied since they can be applied in several fields of biotechnology along with their enzymes. In this context, the characterization of heavy metal resistance determinants in thermophilic microorganisms is the starting point for the development of new biosystems and bioprocesses for environmental monitoring and remediation. This work focuses on the isolation and the genomic exploration of a new arsenic-tolerant microorganism, classified as Alicyclobacillus mali FL18. The bacterium was isolated from a hot mud pool of the solfataric terrains in Pisciarelli, a well-known hydrothermally active zone of the Campi Flegrei volcano near Naples in Italy. A. mali FL18 showed a good tolerance to arsenite (MIC value of 41 mM), as well as to other metals such as nickel (MIC 30 mM), cobalt, and mercury (MIC 3 mM and 17 µM, respectively). Signatures of arsenic resistance genes (one arsenate reductase, one arsenite methyltransferase, and several arsenite exporters) were found interspersed in the genome as well as several multidrug resistance efflux transporters that could be involved in the export of drugs and heavy metal ions. Moreover, the strain showed a high resistance to bacitracin and ciprofloxacin, suggesting that the extreme environment has positively selected multiple resistances to different toxic compounds. This work provides, for the first time, insights into the heavy metal tolerance and antibiotic susceptibility of an Alicyclobacillus strain and highlights its putative molecular determinants.

19.
Int J Biol Macromol ; 153: 608-615, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32165200

RESUMO

To fight oxidative damage due to reactive oxygen species (ROS), cells are equipped of different enzymes, among which Peroxiredoxins (Prxs) (EC 1.11.1.15) play a key role. Prxs are thiol-based enzymes containing one (1-Cys Prx) or two (2-Cys Prx) catalytic cysteine residues. In 2-Cys Prxs the cysteine residues form a disulfide bridge following reduction of peroxide which is in turn reduced by Thioredoxin reductase (Tr) /Thioredoxin (Trx) disulfide reducing system to regenerate the enzyme. In this paper we investigated on Prxs of Thermus thermophilus whose genome contains an ORF TT_C0933 encoding a putative Prx, belonging to the subfamily of Bacterioferritin comigratory protein (Bcp): the synthetic gene was produced and expressed in E. coli and the recombinant protein, TtBcp, was biochemically characterized. TtBcp was active on both organic and inorganic peroxides and showed stability at high temperatures. To get insight into disulfide reducing system involved in the recycling of the enzyme we showed that TtBcp catalically eliminates hydrogen peroxide using an unusual partner, the Protein Disulfide Oxidoreductase (TtPDO) that could replace regeneration of the enzyme. Altogether these results highlight not only a new anti-oxidative pathway but also a promising molecule for possible future biotechnological applications.


Assuntos
Antioxidantes/química , Proteínas de Bactérias/química , Peroxirredoxinas/química , Thermus thermophilus/enzimologia , Antioxidantes/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Peroxirredoxinas/genética , Peroxirredoxinas/metabolismo , Thermus thermophilus/genética
20.
Artigo em Inglês | MEDLINE | ID: mdl-32295125

RESUMO

Microorganisms thriving in hot springs and hydrothermally active volcanic areas are dynamically involved in heavy-metal biogeochemical cycles; they have developed peculiar resistance systems to cope with such metals which nowadays can be considered among the most permanent and toxic pollutants for humans and the environment. For this reason, their exploitation is functional to unravel mechanisms of toxic-metal detoxification and to address bioremediation of heavy-metal pollution with eco-sustainable approaches. In this work, we isolated a novel strain of the thermophilic bacterium Geobacillus stearothermophilus from the solfataric mud pool in Pisciarelli, a well-known hydrothermally active zone of the Campi Flegrei volcano located near Naples in Italy, and characterized it by ribotyping, 16S rRNA sequencing and mass spectrometry analyses. The minimal inhibitory concentration (MIC) toward several heavy-metal ions indicated that the novel G. stearothermophilus isolate is particularly resistant to some of them. Functional and morphological analyses suggest that it is endowed with metal resistance systems for arsenic and cadmium detoxification.


Assuntos
Geobacillus stearothermophilus , Metais Pesados , Biodegradação Ambiental , Geobacillus stearothermophilus/isolamento & purificação , Geobacillus stearothermophilus/fisiologia , Temperatura Alta , Humanos , Itália , Metais Pesados/farmacologia , RNA Ribossômico 16S , Microbiologia da Água
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