Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 51
Filtrar
2.
Sci Total Environ ; 913: 169583, 2024 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-38154629

RESUMO

Lanzarote (Canary Islands, Spain) is one of the best terrestrial analogs to Martian volcanology. Particularly, Lanzarote lava tubes may offer access to recognizably preserved chemical and morphological biosignatures valuable for astrobiology. By combining microbiological, mineralogical, and organic geochemistry tools, an in-depth characterization of speleothems and associated microbial communities in lava tubes of Lanzarote is provided. The aim is to untangle the underlying factors influencing microbial colonization in Earth's subsurface to gain insight into the possibility of similar subsurface microbial habitats on Mars and to identify biosignatures preserved in lava tubes unequivocally. The microbial communities with relevant representativeness comprise chemoorganotrophic, halophiles, and/or halotolerant bacteria that have evolved as a result of the surrounding oceanic environmental conditions. Many of these bacteria have a fundamental role in reshaping cave deposits due to their carbonatogenic ability, leaving behind an organic record that can provide evidence of past or present life. Based on functional profiling, we infer that Crossiella is involved in fluorapatite precipitation via urea hydrolysis and propose its Ca-rich precipitates as compelling biosignatures valuable for astrobiology. In this sense, analytical pyrolysis, stable isotope analysis, and chemometrics were conducted to characterize the complex organic fraction preserved in the speleothems and find relationships among organic families, microbial taxa, and precipitated minerals. We relate organic compounds with subsurface microbial taxa, showing that organic families drive the microbiota of Lanzarote lava tubes. Our data indicate that bacterial communities are important contributors to biomarker records in volcanic-hosted speleothems. Within them, the lipid fraction primarily consists of low molecular weight n-alkanes, α-alkenes, and branched-alkenes, providing further evidence that microorganisms serve as the origin of organic matter in these formations. The ongoing research in Lanzarote's lava tubes will help develop protocols, routines, and predictive models that could provide guidance on choosing locations and methodologies for searching potential biosignatures on Mars.


Assuntos
Marte , Microbiota , Humanos , Meio Ambiente Extraterreno , Minerais , Alcenos
3.
J Fungi (Basel) ; 9(9)2023 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-37755024

RESUMO

With an impressive ability to survive in harsh environments, black fungi are an ecological group of melanized fungi that are widely recognized as a major contributor to the biodeterioration of stone cultural heritage materials. As part of the ongoing efforts to study the fungal diversity thriving in a deteriorated limestone funerary art piece at the Lemos Pantheon, a national monument located in Águeda, Portugal, two isolates of an unknown microcolonial black fungus were retrieved. These isolates were thoroughly studied through a comprehensive analysis based on a multi-locus phylogeny of a combined dataset of ITS rDNA, LSU, and rpb2, along with morphological, physiological, and ecological characteristics. Based on the data obtained from this integrative analysis, we propose a new genus, Saxispiralis gen. nov., and a new species, Saxispiralis lemnorum sp. nov., in the recently described Aeminiaceae family (order Mycosphaerellales). Prior to this discovery, this family only had one known genus and species, Aeminium ludgeri, also isolated from deteriorated limestone. Additionally, considering the isolation source of the fungus and to better understand its potential contribution to the overall stone monument biodeterioration, its in vitro biodeteriorative potential was also evaluated. This work represents a significant contribution to the understanding of the fungal diversity involved in the biodeterioration of limestone heritage.

4.
Biofouling ; 39(2): 204-217, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-37092276

RESUMO

Removing lampenflora, phototrophic organisms developing on rock surfaces in tourist cavities due to the artificial lighting, is a challenge for sustainable and appropriate long-term management of caves. Photosynthetic-based biofilms usually cause rock biodeterioration and an ecological imbalance in cave ecosystems. In this work, a detailed investigation of the effects of the 3 most commonly used lampenflora cleaning operations (NaClO, H2O2 and UVC) was carried out in Pertosa-Auletta Cave (Italy). The application of NaClO showed good disinfection capability over extended periods of time without causing any appreciable rock deterioration. The H2O2 treatment showed to be corrosive for the rock surfaces covered with vermiculation deposits. The chemical alteration of organic and inorganic compounds by H2O2 did not remove biomass, favoring biofilm recovery after three months of treatment. Both NaClO and H2O2 treatments were effective at removing photoautotrophs, although the bacterial phyla Proteobacteria and Bacteroidetes as well as Apicomplexa and Cercozoa among the Eukaryotes, were found to be resistant to these treatments. The UVC treatments did not show any noticeable effect on the biofilms.


Assuntos
Ecossistema , Peróxido de Hidrogênio , Biofilmes , Bactérias , Fotossíntese
5.
J Fungi (Basel) ; 9(4)2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37108954

RESUMO

In this study, we explored the biodiversity and abundance of culturable fungi in four samples associated with different biodeterioration outlines collected from the Lemos Pantheon, a limestone-built artwork in Portugal. We compared the results from prolonged standard freezing with those previously obtained from fresh samples to analyze differences in the obtained community and assess the effectiveness of the standard freezing incubation protocol in uncovering a different segment of culturable fungal diversity. Our results showed a slight decrease in culturable diversity, but over 70% of the obtained isolates were not present in the previously studied fresh samples. We also identified a high number of potential new species with this procedure. Moreover, the use of a wide variety of selective culture media positively influenced the diversity of the cultivable fungi obtained in this study. These findings highlight the importance of developing new protocols under varying conditions to accurately characterize the culturable fraction in a given sample. The identification and study of these communities and their possible contribution to the biodeterioration process is crucial knowledge for formulating effective conservation and restoration plans to prevent further damage to valuable cultural heritage assets.

6.
Gut ; 72(1): 73-89, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-34836918

RESUMO

OBJECTIVE: Idiopathic Parkinson's disease (PD) is characterised by alpha-synuclein (aSyn) aggregation and death of dopaminergic neurons in the midbrain. Recent evidence posits that PD may initiate in the gut by microbes or their toxins that promote chronic gut inflammation that will ultimately impact the brain. In this work, we sought to demonstrate that the effects of the microbial toxin ß-N-methylamino-L-alanine (BMAA) in the gut may trigger some PD cases, which is especially worrying as this toxin is present in certain foods but not routinely monitored by public health authorities. DESIGN: To test the hypothesis, we treated wild-type mice, primary neuronal cultures, cell lines and isolated mitochondria with BMAA, and analysed its impact on gut microbiota composition, barrier permeability, inflammation and aSyn aggregation as well as in brain inflammation, dopaminergic neuronal loss and motor behaviour. To further examine the key role of mitochondria, we also determined the specific effects of BMAA on mitochondrial function and on inflammasome activation. RESULTS: BMAA induced extensive depletion of segmented filamentous bacteria (SFB) that regulate gut immunity, thus triggering gut dysbiosis, immune cell migration, increased intestinal inflammation, loss of barrier integrity and caudo-rostral progression of aSyn. Additionally, BMAA induced in vitro and in vivo mitochondrial dysfunction with cardiolipin exposure and consequent activation of neuronal innate immunity. These events primed neuroinflammation, dopaminergic neuronal loss and motor deficits. CONCLUSION: Taken together, our results demonstrate that chronic exposure to dietary BMAA can trigger a chain of events that recapitulate the evolution of the PD pathology from the gut to the brain, which is consistent with 'gut-first' PD.


Assuntos
Microbioma Gastrointestinal , Doença de Parkinson , Camundongos , Animais , Microbioma Gastrointestinal/fisiologia , Mesencéfalo/metabolismo , Mesencéfalo/patologia , Doença de Parkinson/metabolismo , Inflamação/metabolismo , Mitocôndrias/metabolismo
7.
Microorganisms ; 10(11)2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36422301

RESUMO

Terrestrial isopods are effective herbivorous scavengers with an important ecological role in organic matter cycling. Their guts are considered to be a natural enrichment environment for lignocellulosic biomass (LCB)-degrading bacteria. The main goal of this work was to assess the structural diversity of Porcellio dilatatus gut bacterial communities using NGS technologies, and to predict their functional potential using PICRUSt2 software. Pseudomonadota, Actinomycetota, Bacillota, Cyanobacteria, Mycoplasmatota, Bacteroidota, Candidatus Patescibacteria and Chloroflexota were the most abundant phyla found in P. dilatatus gut bacterial communities. At a family level, we identified the presence of eleven common bacterial families. Functionally, the P. dilatatus gut bacterial communities exhibited enrichment in KEGG pathways related to the functional module of metabolism. With the predicted functional profile of P. dilatatus metagenomes, it was possible to envision putative symbiotic relationships between P. dilatatus gut bacterial communities and their hosts. It was also possible to foresee the presence of a well-adapted bacterial community responsible for nutrient uptake for the host and for maintaining host homeostasis. Genes encoding LCB-degrading enzymes were also predicted in all samples. Therefore, the P. dilatatus digestive tract may be considered a potential source of LCB-degrading enzymes that is not to be neglected.

8.
PLoS One ; 17(10): e0276262, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36251671

RESUMO

Despite the growing interest in the ruminants' gastrointestinal tract (GIT) microbiomes' ability to degrade plant materials by animal husbandry and industrial sectors, only a few studies addressed browsing ruminants. The present work describes the taxonomic and functional profile of the bacterial and archaeal communities from five different gastrointestinal sections (rumen, omasum-abomasum, jejunum, cecum and colon) of browsing Capra hircus, by metabarcoding using 16S rRNA genes hypervariable regions. The bacterial communities across the GITs are mainly composed of Bacillota and Bacteroidota. Prevotella was the leading bacterial group found in the stomachs, Romboutsia in the jejuna, and Rikenellaceae_RC9_gut_group, Bacteroides, UCG-010_ge, UCG-005, and Alistipes in large intestines. The archaeal communities in the stomachs and jejuna revealed to be mainly composed of Methanobrevibacter, while in the large intestines its dominance is shared with Methanocorpusculum. Across the GITs, the main metabolic functions were related to carbohydrate, amino acid, and energy metabolisms. Significant differences in the composition and potential biological functions of the bacterial communities were observed among stomachs, jejuna and large intestines. In contrast, significant differences were observed among stomachs and jejuna verse large intestines for archaeal communities. Overall different regions of the GIT are occupied by different microbial communities performing distinct biological functions. A high variety of glycoside hydrolases (GHs) indispensable for degrading plant cell wall materials were predicted to be present in all the GIT sections.


Assuntos
Microbioma Gastrointestinal , Aminoácidos/metabolismo , Animais , Archaea/genética , Bactérias , Bacteroidetes/genética , Carboidratos , Microbioma Gastrointestinal/genética , Glicosídeo Hidrolases/metabolismo , Cabras/genética , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Rúmen/microbiologia
9.
J Fungi (Basel) ; 8(8)2022 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-36012824

RESUMO

Stone monuments and relics are prone to biodeterioration processes prompted by microbial proliferation and activity. Among the distinct microbes capable of stone colonization, fungi are known to strongly contribute to stone biodeterioration. During the ongoing efforts aiming to study fungi thriving in dolomitic limestone walls of the Coimbra's hypogean Roman cryptoporticus (Portugal), two unknown Bionectriaceae isolates were retrieved. The aim of this work was to depict the molecular and phenotypic characteristics of these microorganisms. The phylogenetic analyses revealed that the studied strains could not be assigned to any of the currently known Bionectriaceae genera. Moreover, the isolates exhibited distinctive and peculiar characteristics, such as the packing of conidia by surrounding hyphal segments and the formation of rope-like microsclerotia with a textura globose. Taking into account all the data obtained, a novel genus and species, Circumfusicillium cavernae gen. et sp. nov. in Bionectriaceae (Hypocreales), is proposed here.

10.
J Pharm Biomed Anal ; 219: 114889, 2022 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-35724611

RESUMO

Urinary tract infections (UTIs) are among the most common infectious diseases worldwide. This type of infections can be healthcare-associated or community-acquired and affects millions of people every year. Different diagnostic procedures are available to detect pathogens in urine and they can be divided into two main categories: laboratory-based and point-of-care (POC) detection techniques. Traditional methodologies are often time-consuming, thus, achieving a rapid and accurate identification of pathogens is a challenging feature that has been pursued by many research groups and companies operating in this area. The purpose of this review is to compare and highlight advantages and disadvantages of the traditional and currently most used detection methods, as well as the emerging POC approaches and the relevant advances in on-site detection of pathogens´ mechanisms, suitable to be adapted to UTI diagnosis. Lately, the commercially available UTI self-testing kits and devices are helping in the diagnosis of urinary infections as patients or care givers are able to perform the test, easily and comfortably at home and, upon the result, decide when to attend an appointment/Urgent Health Care Unit.


Assuntos
Sistemas Automatizados de Assistência Junto ao Leito , Infecções Urinárias , Humanos , Infecções Urinárias/diagnóstico
11.
J Phycol ; 58(2): 219-233, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35133645

RESUMO

The Synechococcales is a large cyanobacterial order comprising both unicellular and filamentous forms, with parietal thylakoid arrangement. Previously, this order has been the subject of taxonomic revisions with new families being erected. During studies of the phototrophic communities on the limestone walls of the Old Cathedral of Coimbra (UNESCO monument), a coccoid Aphanocapsa-like cyanobacterium was isolated. It was characterized using a polyphasic approach, based on morphology, 16S rRNA phylogenetic and phylogenomic analyses, internal transcribed spacer (ITS) secondary structure, and ecology. The 16S rRNA phylogenetic analyses showed that this strain is placed in a separate and highly supported family-level clade, as part of a large group comprising the families Prochlorococcaceae and Prochlorotrichaceae, with Lagosinema as the closest (although quite distant) taxon. Additionally, the phylogenomic analysis also placed this strain in a separate lineage, situated distantly apart from the family Thermosynechococcaceae, but with strains assigned to Acaryochloris marina MBIC 11017 and Aphanocapsa montana BDHKU210001 as the closest taxa. Based on these data, as well as on the results from the secondary ITS structure, morphology, and ecology, we here propose the establishment of Petrachlorosaceae fam. nov., along with the description of Petrachloros gen. nov. and Petrachloros mirabilis sp. nov. We also address additional considerations regarding some cyanobacterial taxa within the order Synechococcales, which we believe deserve further revisions.


Assuntos
Cianobactérias , Mirabilis , Técnicas de Tipagem Bacteriana , Cianobactérias/genética , DNA Bacteriano/genética , Ácidos Graxos , Humanos , Mirabilis/genética , Filogenia , Portugal , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , UNESCO
12.
Int J Syst Evol Microbiol ; 71(12)2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34919038

RESUMO

Fungi are one of the main agents of stone biodeterioration worldwide, since they strongly interfere with its integrity, aesthetical and structural natural properties. During an experimental survey aimed to isolate fungal species contributing to the biodeterioration of the limestone walls of the Old Cathedral of Coimbra (Portuguese unesco World Heritage site), a Talaromyces species that could not be identified to any currently known species in this genus was isolated. Molecular phylogenetic analysis of the internal transcribed spacer, ß-tubulin and RNA polymerase II subunit 2, placed this fungus in Talaromyces sect. Purpurei, while also pointing at its phylogenetic distinction from the remaining species in this section. Thus, a novel species, Talaromyces saxoxalicus sp. nov., is here proposed. Moreover, considering the isolation source of this fungus and in an attempt to understand its contribution to the overall stone monument biodeterioration, the species's in vitro biodeteriorative potential was also evaluated. The results highlighted that the species exhibited an in vitro biodeteriorative ability (calcium oxalate crystal formation), highlighting its potential deteriorative profile.


Assuntos
Filogenia , Talaromyces , Carbonato de Cálcio , DNA Fúngico/genética , Técnicas de Tipagem Micológica , Portugal , Análise de Sequência de DNA , Talaromyces/classificação , Talaromyces/isolamento & purificação
13.
Microorganisms ; 9(4)2021 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-33808176

RESUMO

The "University of Coimbra-Alta and Sofia" area was awarded the UNESCO World Heritage Site distinction in 2013. The Old Cathedral of Coimbra, a 12th-century limestone monument located in this area, has been significantly impacted during the last 800 years by physical, chemical, and biological processes. This led to the significant deterioration of some of its structures and carvings, with loss of aesthetical, cultural, and historical values. For this work, deteriorated spots of the walls of three semi-open chapels from the cloister of the Cathedral were sampled to ascertain their bacterial and archaeal structural diversity. Based on Next-Generation Sequencing (NGS) result analysis, we report the presence of microbial populations that are well adapted to an ecosystem with harsh conditions and that can establish a diverse biofilm in most cases. While it was possible to determine dominant phylogenetic groups in Archaea and Bacteria domains, there was no clear connection between specific core microbiomes and the different deterioration patterns analyzed. The distribution of these archaeal and bacterial communities within the analyzed biodeterioration spots suggests they are more influenced by abiotic factors (i.e., water availability, salinity, etc.), although they influence (and are influenced by) the algal and fungal population composition in this ecosystem. This work provides valuable information that can assist in establishing future guidelines for the preservation and conservation of this kind of historic stone monuments.

15.
Microorganisms ; 8(6)2020 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-32575724

RESUMO

Pseudomonassyringae pv. actinidiae (Psa) is a gram-negative bacterium responsible for the bacterial canker in Actinidia chinensis var. deliciosa and A. chinensis var. chinensis, a quarantine organism threatening the kiwifruit industry sustainability. The present study aimed to determine the genetic structure of the endophytic and epiphytic populations of Psa isolated from four different Portuguese orchards with distinct abiotic conditions in two consecutive seasons. The results identified several coexisting and highly heterogeneous Psa populations. Moreover, evident changes in population structure occurred between the epiphytic and endophytic populations, and between seasons with a notable decrease in Psa diversity in autumn. This work provided solid evidence that the initial clonal expansion of Psa in Europe was followed by a wide genomic diversification. This perspective is important for the understanding of kiwifruit bacterial canker disease occurrence and Psa evolution, namely when adopting strategies for management of epidemics.

16.
Microbiol Resour Announc ; 9(26)2020 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-32586873

RESUMO

The recently described species Myxacorys almedinensis and two other cyanobacteria were isolated from the limestone walls of the Old Cathedral of Coimbra, Portugal (UNESCO World Heritage Site). The high-quality genome sequences presented here will be essential for characterization purposes and description of the novel taxa.

17.
Int J Syst Evol Microbiol ; 70(3): 1596-1604, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32228748

RESUMO

We performed high-quality genome sequencing of eight strains of the species of the genus Tepidimonas and examined the genomes of closely related strains from the databases to understand why Tepidimonas taiwanensis is the only strain of this genus that utilizes glucose and fructose for growth. We found that the assimilation of these hexoses by T. taiwanensis was due to the presence of two transporters that are absent in all other genomes of strains of members of the genus Tepidimonas examined. Some strains lack genes coding for glucokinase, but the Embden-Meyerhof-Parnas pathway appears to be otherwise complete. The pentose phosphate pathway has a complete set of genes, but genes of the Entner-Doudoroff pathway were not identified in the genomes of any of the strains examined. Genome analysis using average nucleotide identity (ANIb), digital DNA-DNA hybridization (dDDH), average amino acid identity (AAI) and phylogenetic analysis of 400 conserved genes was performed to assess the taxonomic classification of the organisms. Two isolates of the genus Tepidimonas from the hot spring at São Pedro do Sul, Portugal, designated SPSP-6T and SPSPC-18 were also examined in this study. These organisms are mixotrophic, have an optimum growth temperature of about 50 ºC, utilize several organic acids and amino acids for growth but do not grow on sugars. Distinctive phenotypic, 16S rRNA gene sequence and genomic characteristics of strains SPSP-6T and SPSPC-18 lead us to propose a novel species based on strain SPSP-6T for which we recommend the name Tepidimonas charontis sp. nov. (=CECT 9683T=LMG 30884T).


Assuntos
Burkholderiales/classificação , Fontes Termais/microbiologia , Filogenia , Técnicas de Tipagem Bacteriana , Composição de Bases , Burkholderiales/isolamento & purificação , Hibridização Genômica Comparativa , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Portugal , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Microbiologia da Água
18.
Microbiol Resour Announc ; 8(21)2019 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-31123018

RESUMO

Nontuberculous mycobacteria (NTM), some of which had multidrug-resistant profiles, were isolated from a tertiary care hospital setting. Although most NTM are nonpathogenic, contamination of hospital surfaces by these opportunistic pathogens poses a health risk to vulnerable inpatients. These high-quality NTM draft genomes are fundamental for future genetic and epidemiological studies.

19.
Microbiol Resour Announc ; 8(14)2019 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-30948467

RESUMO

Aeminium ludgeri is an extremotolerant microcolonial black fungus isolated from a biodeteriorated limestone art piece in the Old Cathedral of Coimbra, Portugal (a UNESCO World Heritage Site). The high-quality draft genome sequence of Aeminium ludgeri presented here represents the first sequenced genome for both the recently described fungal family Aeminiaceae and the genus Aeminium.

20.
Microbiol Resour Announc ; 8(12)2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30938702

RESUMO

Crenobacter cavernae CAVE-375 and Oxalobacteriaceae sp. strain CAVE-383, two Gram-negative bacteria, were isolated during the first microbiology survey performed in a karst cave in Portugal. We report here the release of their high-quality draft genome sequences, which will be useful for geographic-ecological purposes and the description of novel taxa.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA