Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
1.
Archaeol Anthropol Sci ; 16(7): 97, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38854990

RESUMO

Rice and millet arrived in Western Japan from Korea around 3,000 years ago and spread eastwards across the archipelago in the next 700 years. However, the extent to which agriculture transformed traditional Jomon hunter-gatherer-fisher communities is debated. Central Japan is a key area of study as remodelling of radiocarbon dates shows a slowdown in the dispersal rate of rice agriculture in this area. Here, we examine and compare the use of pottery by Final Jomon and Early to Middle Yayoi communities in the Tokai and the Central Highland regions of central Japan, using lipid residue analysis. Although the identification of specific biomarkers for rice remains elusive, an increase in the ratio of E/H C18 APAAs with the arrival of rice and millet indicates a potential change in plant processing and consumption. We were also able to identify biomarkers for broomcorn millet (miliacin) in both Final Jomon and Yayoi pottery. However, evidence for millet consumption is sparse and in all cases was likely mixed with wild hunted and foraged foods. We conclude therefore that, despite the introduction of rice and millet agriculture in central Japan, pre-existing diets and culinary habits of Jomon hunter-gatherers remain important. Supplementary Information: The online version contains supplementary material available at 10.1007/s12520-024-01992-9.

2.
Sci Adv ; 9(49): eadk5201, 2023 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-38064558

RESUMO

The introduction of domestic horses transformed Indigenous societies across the grasslands of Argentina, leading to the emergence of specialized horse cultures across the Southern Cone. However, the dynamics of this introduction are poorly chronicled by historic records. Here, we apply archaeozoological and biomolecular techniques to horse remains from the site of Chorrillo Grande 1 in southern Argentina. Osteological and taphonomic analyses suggest that horses were pastorally managed and used for food by Aónikenk/Tehuelche hunter-gatherers before the onset of permanent European settlement, as early as the mid-17th century. DNA-based sex identifications suggest consumption of both male and female horses, while ceramic residue also shows use of guanaco products. Sequential isotope analyses on horse dentition reveal an origin in southern Patagonia and movement of these animals between the Río Coig and Río Gallegos basins. These results reinforce emerging evidence for rapid Indigenous-mediated dispersal of horses in the Americas and demonstrate that horses catalyzed rapid economic and social transformations.


Assuntos
Alimentos , Animais , Cavalos , Masculino , Feminino , Argentina
3.
Sci Rep ; 13(1): 16771, 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37798303

RESUMO

Understanding long-term dynamics of past socio-ecological systems is essential for their future management. The southern Atlantic Forest coast of Brazil with its biodiverse littoral zone and artisanal fishing communities, is a priority for conservation. Traditional maritime knowledge is thought to have a deep-history and indeed, marine exploitation can be traced back to the middle Holocene. As part of one of South America's largest diasporas, Guarani groups reached the southern Brazilian coast at around 1000 years ago. Their impact on the long-standing coastal economy is unknown, due to poor preservation of organic remains. Through the first organic residue study on Guarani pottery, we show that maize rather than aquatic foods was the most dominant product in pottery at this time. By developing a mixing model based on carbon isotope values of saturated and mono-unsaturated fatty acids we propose new criteria for the identification of maize, opening up avenues for future research. Our data confirms the importance of maize to the pre-colonial Guarani, even in a highly productive coastal environment. The Guarani occupation of this region marks a significant departure from previous socio-economic systems, potentially leading to loss of traditional knowledge and alleviating anthropogenic pressure, albeit temporarily, on the marine environment.

4.
Proc Natl Acad Sci U S A ; 120(43): e2310138120, 2023 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-37844237

RESUMO

To investigate changes in culinary practices associated with the arrival of farming, we analysed the organic residues of over 1,000 pottery vessels from hunter-gatherer-fisher and early agricultural sites across Northern Europe from the Lower Rhine Basin to the Northeastern Baltic. Here, pottery was widely used by hunter-gatherer-fishers prior to the introduction of domesticated animals and plants. Overall, there was surprising continuity in the way that hunter-gatherer-fishers and farmers used pottery. Both aquatic products and wild plants remained prevalent, a pattern repeated consistently across the study area. We argue that the rapid adaptation of farming communities to exploit coastal and lagoonal resources facilitated their northerly expansion, and in some cases, hunting, gathering, and fishing became the most dominant subsistence strategy. Nevertheless, dairy products frequently appear in pottery associated with the earliest farming groups often mixed with wild plants and fish. Interestingly, we also find compelling evidence of dairy products in hunter-gatherer-fisher Ertebølle pottery, which predates the arrival of domesticated animals. We propose that Ertebølle hunter-gatherer-fishers frequently acquired dairy products through exchange with adjacent farming communities prior to the transition. The continuity observed in pottery use across the transition to farming contrasts with the analysis of human remains which shows substantial demographic change through ancient DNA and, in some cases, a reduction in marine consumption through stable isotope analysis. We postulate that farmers acquired the knowledge and skills they needed to succeed from local hunter-gatherer-fishers but without substantial admixture.


Assuntos
Agricultura , Arqueologia , Animais , Humanos , Europa (Continente) , Fazendas , Fazendeiros
5.
R Soc Open Sci ; 10(3): 221305, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36908986

RESUMO

From the 9th to 14th centuries AD, Sicily experienced a series of rapid and quite radical changes in political regime, but the impact of these regime changes on the lives of the people that experienced them remains largely elusive within the historical narrative. We use a multi-faceted lipid residue approach to give direct chemical evidence of the use of 248 everyday domestic ceramic containers from Islamic and post-Islamic contexts in western Sicily to aid our understanding of daily habits throughout this period of political change. A range of commodities was successfully identified, including animal fats, vegetable products, fruit products (potentially including wine) and plant resins. The study highlights the complexity of residues in early medieval Mediterranean society as, in many cases, mixtures of commodities were observed reflecting sequential cooking events and/or the complex mixtures reflective of medieval recipes. However, overall, there were no clear changes in the composition of the residues following the imposition of Norman control over the island and through subsequent periods, despite some differences between urban centres and rural sites. Thus, lending to the idea that post-Islamic populations largely flourished and benefited from the agricultural systems, resources and recipes left by their predecessors.

6.
Proc Biol Sci ; 290(1993): 20221330, 2023 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-36809804

RESUMO

Determining the degree to which humans relied on coastal resources in the past is key for understanding long-term social and economic development, as well as for assessing human health and anthropogenic impacts on the environment. Prehistoric hunter-gatherers are often assumed to have heavily exploited aquatic resources, especially those living in regions of high marine productivity. For the Mediterranean, this view has been challenged, partly by the application of stable isotope analysis of skeletal remains which has shown more varied coastal hunter-gatherer diets than in other regions, perhaps due to its lower productivity. By undertaking a more specific analysis of amino acids from bone collagen of 11 individuals from one of the oldest and best-known Mesolithic cemeteries in the Mediterranean, at El Collado, Valencia, we show that high levels of aquatic protein consumption were achieved. By measuring both carbon and nitrogen in amino acids, we conclude that some of the El Collado humans relied heavily on local lagoonal fish and possibly shellfish, rather than open marine species. By contrast to previous suggestions, this study demonstrates that the north-western coast of the Mediterranean basin could support maritime-oriented economies during the Early Holocene.


Assuntos
Aminoácidos , Isótopos , Animais , Humanos , Nitrogênio , Colágeno/química , Carbono
7.
Nat Hum Behav ; 7(2): 171-183, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36550220

RESUMO

Human history has been shaped by global dispersals of technologies, although understanding of what enabled these processes is limited. Here, we explore the behavioural mechanisms that led to the emergence of pottery among hunter-gatherer communities in Europe during the mid-Holocene. Through radiocarbon dating, we propose this dispersal occurred at a far faster rate than previously thought. Chemical characterization of organic residues shows that European hunter-gatherer pottery had a function structured around regional culinary practices rather than environmental factors. Analysis of the forms, decoration and technological choices suggests that knowledge of pottery spread through a process of cultural transmission. We demonstrate a correlation between the physical properties of pots and how they were used, reflecting social traditions inherited by successive generations of hunter-gatherers. Taken together the evidence supports kinship-driven, super-regional communication networks that existed long before other major innovations such as agriculture, writing, urbanism or metallurgy.


Assuntos
Agricultura , Tecnologia , Humanos , Datação Radiométrica , Europa (Continente)
8.
Sci Adv ; 7(35)2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34433561

RESUMO

The remains of those who perished at Herculaneum in 79 CE offer a unique opportunity to examine lifeways across an ancient community who lived and died together. Historical sources often allude to differential access to foodstuffs across Roman society but provide no direct or quantitative information. By determining the stable isotope values of amino acids from bone collagen and deploying Bayesian models that incorporate knowledge of protein synthesis, we were able to reconstruct the diets of 17 adults from Herculaneum with unprecedented resolution. Significant differences in the proportions of marine and terrestrial foods consumed were observed between males and females, implying that access to food was differentiated according to gender. The approach also provided dietary data of sufficient precision for comparison with assessments of food supply to modern populations, opening up the possibility of benchmarking ancient diets against contemporary settings where the consequences for health are better understood.

9.
J Infect Dis ; 224(1): 151-163, 2021 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-33336702

RESUMO

We estimated vaccine effectiveness (VE) for prevention of influenza-associated hospitalizations among adults during the 2018-2019 influenza season. Adults admitted with acute respiratory illness to 14 hospitals of the US Hospitalized Adult Influenza Vaccine Effectiveness Network (HAIVEN) and testing positive for influenza were cases; patients testing negative were controls. VE was estimated using logistic regression and inverse probability of treatment weighting. We analyzed data from 2863 patients with a mean age of 63 years. Adjusted VE against influenza A(H1N1)pdm09-associated hospitalization was 51% (95% confidence interval [CI], 25%-68%). Adjusted VE against influenza A(H3N2) virus-associated hospitalization was -2% (95% CI, -65% to 37%) and differed significantly by age, with VE of -130% (95% CI, -374% to -27%) among adults 18 to ≤56 years of age. Although vaccination halved the risk of influenza A(H1N1)pdm09-associated hospitalizations, it conferred no protection against influenza A(H3N2)-associated hospitalizations. We observed negative VE for young and middle-aged adults but cannot exclude residual confounding as a potential explanation.


Assuntos
Hospitalização , Vacinas contra Influenza/imunologia , Vacinação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
11.
R Soc Open Sci ; 7(4): 192016, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32431883

RESUMO

The introduction of pottery vessels to Europe has long been seen as closely linked with the spread of agriculture and pastoralism from the Near East. The adoption of pottery technology by hunter-gatherers in Northern and Eastern Europe does not fit this paradigm, and its role within these communities is so far unresolved. To investigate the motivations for hunter-gatherer pottery use, here, we present the systematic analysis of the contents of 528 early vessels from the Baltic Sea region, mostly dating to the late 6th-5th millennium cal BC, using molecular and isotopic characterization techniques. The results demonstrate clear sub-regional trends in the use of ceramics by hunter-gatherers; aquatic resources in the Eastern Baltic, non-ruminant animal fats in the Southeastern Baltic, and a more variable use, including ruminant animal products, in the Western Baltic, potentially including dairy. We found surprisingly little evidence for the use of ceramics for non-culinary activities, such as the production of resins. We attribute the emergence of these sub-regional cuisines to the diffusion of new culinary ideas afforded by the adoption of pottery, e.g. cooking and combining foods, but culturally contextualized and influenced by traditional practices.

12.
Geobiology ; 18(4): 497-507, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32180328

RESUMO

Methane emissions from peat bogs are mitigated by methanotrophs, which live in symbiosis with peat moss (e.g. Sphagnum). Here, we investigate the influence of temperature and resultant changes in methane fluxes on Sphagnum and methanotroph-related biomarkers, evaluating their potential as proxies in ancient bogs. A pulse-chase experiment using 13 C-labelled methane in the field clearly showed label uptake in diploptene, a biomarker for methanotrophs, demonstrating in situ methanotrophic activity in Sphagnum under natural conditions. Peat cores containing live Sphagnum were incubated at 5, 10, 15, 20 and 25°C for two months, causing differences in net methane fluxes. The natural δ13 C values of diploptene extracted from Sphagnum showed a strong correlation with temperature and methane production. The δ13 C values ranged from -34‰ at 5°C to -41‰ at 25°C. These results are best explained by enhanced expression of the methanotrophic enzymatic isotope effect at higher methane concentrations. Hence, δ13 C values of diploptene, or its diagenetic products, potentially provide a useful tool to assess methanotrophic activity in past environments. Increased methane fluxes towards Sphagnum did not affect δ13 C values of bulk Sphagnum and its specific marker, the C23 n-alkane. The concentration of methanotroph-specific bacteriohopanepolyols (BHPs), aminobacteriohopanetetrol (aminotetrol, characteristic for type II and to a lesser extent type I methanotrophs) and aminobacteriohopanepentol (aminopentol, a marker for type I methanotrophs) showed a non-linear response to increased methane fluxes, with relatively high abundances at 25°C compared to those at 20°C or below. Aminotetrol was more abundant than aminopentol, in contrast to similar abundances of aminotetrol and aminopentol in fresh Sphagnum. This probably indicates that type II methanotrophs became prevalent under the experimental conditions relative to type I methanotrophs. Even though BHP concentrations may not directly reflect bacterial activity, they may provide insight into the presence of different types of methanotrophs.


Assuntos
Methylococcaceae , Sphagnopsida , Isótopos de Carbono , Metano , Solo , Microbiologia do Solo , Temperatura , Áreas Alagadas
13.
J Hepatol ; 69(5): 1123-1135, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30006067

RESUMO

BACKGROUND & AIMS: Primary biliary cholangitis (PBC) is an autoimmune-associated chronic liver disease triggered by environmental factors, such as exposure to xenobiotics, which leads to a loss of tolerance to the lipoic acid-conjugated regions of the mitochondrial pyruvate dehydrogenase complex, typically to the E2 component. We aimed to identify xenobiotics that might be involved in the environmental triggering of PBC. METHODS: Urban landfill and control soil samples from a region with high PBC incidence were screened for xenobiotic activities using analytical, cell-based xenobiotic receptor activation assays and toxicity screens. RESULTS: A variety of potential xenobiotic classes were ubiquitously present, as identified by their interaction with xenobiotic receptors - aryl hydrocarbon receptor, androgen receptor and peroxisome proliferator activated receptor alpha - in cell-based screens. In contrast, xenoestrogens were present at higher levels in soil extracts from around an urban landfill. Furthermore, two landfill sampling sites contained a chemical(s) that inhibited mitochondrial oxidative phosphorylation and induced the apoptosis of a hepatic progenitor cell. The mitochondrial effect was also demonstrated in human liver cholangiocytes from three separate donors. The chemical was identified as the ionic liquid [3-methyl-1-octyl-1H-imidazol-3-ium]+ (M8OI) and the toxic effects were recapitulated using authentic pure chemical. A carboxylate-containing human hepatocyte metabolite of M8OI, bearing structural similarity to lipoic acid, was also enzymatically incorporated into the E2 component of the pyruvate dehydrogenase complex via the exogenous lipoylation pathway in vitro. CONCLUSIONS: These results identify, for the first time, a xenobiotic in the environment that may be related to and/or be a component of an environmental trigger for PBC. Therefore, further study in experimental animal models is warranted, to determine the risk of exposure to these ionic liquids. LAY SUMMARY: Primary biliary cholangitis is a liver disease in which most patients have antibodies to mitochondrial proteins containing lipoic acid binding site(s). This paper identified a man-made chemical present in soils around a waste site. It was then shown that this chemical was metabolized into a product with structural similarity to lipoic acid, which was capable of replacing lipoic acid in mitochondrial proteins.


Assuntos
Colangite/induzido quimicamente , Imidazóis/toxicidade , Poluentes do Solo/toxicidade , Xenobióticos/toxicidade , Trifosfato de Adenosina/metabolismo , Animais , Células Cultivadas , Receptor alfa de Estrogênio/efeitos dos fármacos , Células Hep G2 , Humanos , Imidazóis/isolamento & purificação , Fígado/efeitos dos fármacos , Camundongos , Mitocôndrias Hepáticas/efeitos dos fármacos , Praguicidas/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Ratos , Poluentes do Solo/análise , Xenobióticos/isolamento & purificação
14.
PLoS One ; 12(10): e0186360, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29036222

RESUMO

The recent proliferation of harmful cyanobacterial blooms (cyanoHABs) in the Baltic and other marginal seas poses a severe threat for the health of infested ecosystems as e.g. the massive export and decay of cyanobacterial biomass facilitates the spread of bottom water hypoxia. There is evidence that cyanoHABs occurred repeatedly in the Baltic Sea but knowledge of their spatiotemporal distribution and the cyanobacteria that contributed to them is limited. In this study, we examined representatives of the major bloom-forming heterocystous cyanobacteria (i.e. Aphanizomenon, Dolichospermum (formerly Anabaena) and Nodularia) to establish lipid fingerprints that allow tracking these environmentally important diazotrophs in the modern and past Baltic Sea. The distribution of normal and mid-chain branched alkanes, fatty acid methyl esters, bacteriohopanepolyols and heterocyst glycolipids permitted a clear chemotaxonomic separation of the different heterocystous cyanobacteria but also indicated a close phylogenetic relationship between representatives of the genera Aphanizomenon and Dolichospermum. Compared to the discontinuous nature of phytoplankton surveys studies, the distinct lipid profiles reported here will allow obtaining detailed spatiotemporal information on the frequency and intensity of Baltic Sea cyanoHABs as well as their community composition using the time-integrated biomarker signatures recorded in surface and subsurface sediments. As heterocystous cyanobacteria of the genera Aphanizomenon, Dolichospermum and Nodularia are generally known to form massive blooms in many brackish as well as lacustrine systems worldwide, the chemotaxonomic markers introduced in this study may allow investigating cyanoHABs in a great variety of contemporary environments from polar to tropical latitudes.


Assuntos
Cianobactérias/metabolismo , Metabolismo dos Lipídeos , Oceanos e Mares , Biodiversidade , Biomarcadores/química , Biomarcadores/metabolismo , Cianobactérias/classificação , Cianobactérias/fisiologia , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Glicolipídeos/metabolismo , Hidrocarbonetos/química , Hidrocarbonetos/metabolismo , Fixação de Nitrogênio
15.
Environ Microbiol Rep ; 9(5): 492-500, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28772060

RESUMO

Interpretation of bacteriohopanepolyol (BHP) biomarkers tracing microbiological processes in modern and ancient sediments relies on understanding environmental controls of production and preservation. BHPs from methanotrophs (35-aminoBHPs) were studied in methane-amended aerobic river-sediment incubations at different temperatures. It was found that: (i) With increasing temperature (4°C-40°C) a 10-fold increase in aminopentol (associated with Crenothrix and Methylobacter spp. growth) occurred with only marginal increases in aminotriol and aminotetrol; (ii) A further increase in temperature (50°C) saw selection for the thermophile Methylocaldum and mixtures of aminopentol and C-3 methylated aminopentol, again, with no increase in aminotriol and aminotetrol. (iii) At 30°C, more aminopentol and an aminopentol isomer and unsaturated aminopentol were produced after methanotroph growth and the onset of substrate starvation/oxygen depletion. (iv) At 50°C, aminopentol and C-3 methylated aminopentol, only accumulated during growth but were clearly resistant to remineralization despite cell death. These results have profound implications for the interpretation of aminoBHP distributions and abundances in modern and past environments. For instance, a temperature regulation of aminopentol production but not aminotetrol or aminotriol is consistent with and, corroborative of, observed aminopentol sensitivity to climate warming recorded in a stratigraphic sequence deposited during the Paleocene-Eocene thermal maximum (PETM).


Assuntos
Microbiologia Ambiental , Metano/metabolismo , Methylococcaceae/classificação , Methylococcaceae/fisiologia , Viabilidade Microbiana , Temperatura , Ácidos Carboxílicos/metabolismo , Meio Ambiente , Sedimentos Geológicos/microbiologia
16.
Trials ; 18(1): 401, 2017 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-28851399

RESUMO

BACKGROUND: Surgical site infections (SSIs) are common, occurring in up to 25% of > 4 million operations performed in England each year. Previous trials of the effect of wound dressings on the risk of developing a SSI are of poor quality and underpowered. METHODS/DESIGN: This study is a feasibility and pilot trial to examine the feasibility of a full trial that will compare simple dressings, no dressing and tissue-glue as a dressing. It is examining the overall acceptability of trial participation, identifying opportunities for refinement, testing the feasibility of and validating new outcome tools to assess SSI, wound management issues and patients' wound symptom experiences. It is also exploring methods for avoiding performance bias and blinding outcome assessors by testing the feasibility of collecting wound photographs taken in theatre immediately after wound closure and, at 4-8 weeks after surgery, taken by participants themselves or their carers. Finally, it is identifying the main cost drivers for an economic evaluation of dressing types. Integrated qualitative research is exploring acceptability and reasons for non-adherence to allocation. Adults undergoing primary elective or unplanned abdominal general surgery or Caesarean section are eligible. The main exclusion criteria are abdominal or other major surgery less than three months before the index operation or contraindication to dressing allocation. The trial is scheduled to recruit for nine months. The findings will be used to inform the design of a main trial. DISCUSSION: This pilot trial is the first pragmatic study to randomise participants to no dressing or tissue-glue as a dressing versus a simple dressing. Early evidence from the ongoing pilot shows that recruitment is proceeding well and that the interventions are acceptable to participants. Combined with the qualitative findings, the findings will inform whether a main, large trial is feasible and, if so, how it should be designed. TRIAL REGISTRATION: ISRCTN49328913 . Registered on 20 October 2015.


Assuntos
Abdome/cirurgia , Bandagens , Cesárea , Infecção da Ferida Cirúrgica/prevenção & controle , Ferida Cirúrgica/terapia , Adesivos Teciduais/uso terapêutico , Bandagens/efeitos adversos , Cesárea/efeitos adversos , Protocolos Clínicos , Estudos de Viabilidade , Feminino , Humanos , Masculino , Projetos Piloto , Projetos de Pesquisa , Ferida Cirúrgica/microbiologia , Infecção da Ferida Cirúrgica/diagnóstico , Infecção da Ferida Cirúrgica/microbiologia , Fatores de Tempo , Adesivos Teciduais/efeitos adversos , Resultado do Tratamento , Reino Unido , Técnicas de Fechamento de Ferimentos/efeitos adversos , Cicatrização
17.
PLoS One ; 11(11): e0165635, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27824887

RESUMO

Aerobic methane oxidation (AMO) is one of the primary biologic pathways regulating the amount of methane (CH4) released into the environment. AMO acts as a sink of CH4, converting it into carbon dioxide before it reaches the atmosphere. It is of interest for (paleo)climate and carbon cycling studies to identify lipid biomarkers that can be used to trace AMO events, especially at times when the role of methane in the carbon cycle was more pronounced than today. AMO bacteria are known to synthesise bacteriohopanepolyol (BHP) lipids. Preliminary evidence pointed towards 35-aminobacteriohopane-30,31,32,33,34-pentol (aminopentol) being a characteristic biomarker for Type I methanotrophs. Here, the BHP compositions were examined for species of the recently described novel Type I methanotroph bacterial genera Methylomarinum and Methylomarinovum, as well as for a novel species of a Type I Methylomicrobium. Aminopentol was the most abundant BHP only in Methylomarinovum caldicuralii, while Methylomicrobium did not produce aminopentol at all. In addition to the expected regular aminotriol and aminotetrol BHPs, novel structures tentatively identified as methylcarbamate lipids related to C-35 amino-BHPs (MC-BHPs) were found to be synthesised in significant amounts by some AMO cultures. Subsequently, sediments and authigenic carbonates from methane-influenced marine environments were analysed. Most samples also did not contain significant amounts of aminopentol, indicating that aminopentol is not a useful biomarker for marine aerobic methanotophic bacteria. However, the BHP composition of the marine samples do point toward the novel MC-BHPs components being potential new biomarkers for AMO.


Assuntos
Organismos Aquáticos/metabolismo , Ecossistema , Methylococcaceae/metabolismo , Aerobiose , Biomarcadores/metabolismo , Ácidos Carboxílicos/metabolismo , Sedimentos Geológicos/análise , Sedimentos Geológicos/microbiologia , Lipídeos/análise , Metano/metabolismo
18.
Rapid Commun Mass Spectrom ; 30(19): 2087-98, 2016 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-27472174

RESUMO

RATIONALE: Traditional investigation of bacteriohopanepolyols (BHPs) has relied on derivatisation by acetylation prior to gas chromatography/mass spectrometry (GC/MS) or liquid chromatography/MS (LC/MS) analysis. Here, modern chromatographic techniques (ultrahigh-performance liquid chromatography (UPLC)) and new column chemistries were tested to develop a method for BHP analysis without the need for derivatisation. METHODS: Bacterial culture and sedimentary lipid extracts were analysed using a Waters Acquity Xevo TQ-S triple quadrupole mass spectrometer in positive ion atmospheric pressure chemical ionisation (APCI) mode. Waters BEH C18 and ACE Excel C18 were the central columns evaluated using a binary solvent gradient with 0.1% formic acid in the polar solvent phase in order to optimise performance and selectivity. RESULTS: Non-amine BHPs and adenosylhopane showed similar performance on each C18 column; however, BHP-containing terminal amines were only identified eluting from the ultra-inert ACE Excel C18 column. APCI-MS/MS product ion scans revealed significant differences in fragmentation pathways from previous methods for acetylated compounds. The product ions used for targeted multiple reaction monitoring (MRM) are summarised. CONCLUSIONS: UPLC/MS/MS analysis using an ACE Excel C18 column produced superior separation for amine-containing BHPs and reduced run times from 60 to 9 min compared with previous methods. Unexpected variations in fragmentation pathways between structural subgroups must be taken into account when optimising MRM transitions for future quantitative studies. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Lipídeos de Membrana/química , Methylococcus capsulatus/química , Methylosinus trichosporium/química , Espectrometria de Massas em Tandem/métodos , Lipídeos de Membrana/metabolismo , Methylococcus capsulatus/metabolismo , Methylosinus trichosporium/metabolismo , Estrutura Molecular
19.
Environ Microbiol Rep ; 8(1): 122-31, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26617278

RESUMO

River Tyne (UK) estuarine sediments harbour a genetically and functionally diverse community of methane-oxidizing bacteria (methanotrophs), the composition and activity of which were directly influenced by imposed environmental conditions (pH, salinity, temperature) that extended far beyond those found in situ. In aerobic sediment slurries methane oxidation rates were monitored together with the diversity of a functional gene marker for methanotrophs (pmoA). Under near in situ conditions (4-30°C, pH 6-8, 1-15 g l(-1) NaCl), communities were enriched by sequences affiliated with Methylobacter and Methylomonas spp. and specifically a Methylobacter psychrophilus-related species at 4-21°C. More extreme conditions, namely high temperatures ≥ 40°C, high ≥ 9 and low ≤ 5 pH, and high salinities ≥ 35 g l(-1) selected for putative thermophiles (Methylocaldum), acidophiles (Methylosoma) and haloalkaliphiles (Methylomicrobium). The presence of these extreme methanotrophs (unlikely to be part of the active community in situ) indicates passive dispersal from surrounding environments into the estuary.


Assuntos
Biota/efeitos dos fármacos , Biota/efeitos da radiação , Água Doce/microbiologia , Metano/metabolismo , Methylococcaceae/classificação , Salinidade , Temperatura , Aerobiose , Estuários , Concentração de Íons de Hidrogênio , Methylococcaceae/genética , Methylococcaceae/crescimento & desenvolvimento , Methylococcaceae/metabolismo , Cloreto de Sódio/metabolismo , Reino Unido
20.
Chembiochem ; 15(14): 2156-61, 2014 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-25155017

RESUMO

Wild-type Streptomyces coelicolor A3(2) produces aminobacteriohopanetriol as the only elongated C35 hopanoid. The hopanoid phenotype of two mutants bearing a deletion of genes from a previously identified hopanoid biosynthesis gene cluster provides clues to the formation of C35 bacteriohopanepolyols. orf14 encodes a putative nucleosidase; its deletion induces the accumulation of adenosylhopane as it cannot be converted into ribosylhopane. orf18 encodes a putative transaminase; its deletion results in the accumulation of adenosylhopane, ribosylhopane, and bacteriohopanetetrol. Ribosylhopane was postulated twenty years ago as a precursor for bacterial hopanoids but was never identified in a bacterium. Absence of the transaminase encoded by orf18 prevents the reductive amination of ribosylhopane into aminobacteriohopanetriol and induces its accumulation. Its reduction by an aldose-reductase-like enzyme produces bacteriohopanetetrol, which is normally not present in S. coelicolor.


Assuntos
Streptomyces coelicolor/metabolismo , Triterpenos/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Vias Biossintéticas , Deleção de Genes , Genes Bacterianos , Família Multigênica , N-Glicosil Hidrolases/genética , N-Glicosil Hidrolases/metabolismo , Streptomyces coelicolor/química , Streptomyces coelicolor/genética , Transaminases/genética , Transaminases/metabolismo , Triterpenos/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...