Publications by authors named "B M Dellagnezze"

Article Synopsis
  • Methane-cycling is increasingly important in high-latitude ecosystems as global warming releases more organic carbon from permafrost, leading to the study of 387 samples from regions like Siberia, Alaska, and Patagonia.
  • The research integrated physicochemical, climatic, and geographic data with microbial genetic sequences to analyze the structure of methane-related microbial communities, showing that pH significantly influences community composition.
  • Key bioindicator taxa associated with different ecological conditions were identified, such as Methanoregula as generalist methanogens and specific methanotrophs like Methylocystis and Methylobacter, highlighting their role in understanding methane cycling and its impact on greenhouse gas emissions under climate change.
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Petroleum is a very complex and diverse organic mixture. Its composition depends on reservoir location and conditions and changes once crude oil is spilled into the environment, making the characteristics associated with every spill unique. Polycyclic aromatic hydrocarbons (PAHs) are common components of the crude oil and constitute a group of persistent organic pollutants.

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Microorganisms have shown their ability to colonize extreme environments including deep subsurface petroleum reservoirs. Physicochemical parameters may vary greatly among petroleum reservoirs worldwide and so do the microbial communities inhabiting these different environments. The present work aimed at the characterization of the microbiota in biodegraded and non-degraded petroleum samples from three Brazilian reservoirs and the comparison of microbial community diversity across oil reservoirs at local and global scales using 16S rRNA clone libraries.

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Microbial degradation of petroleum is a worldwide issue, which causes physico-chemical changes in its compounds, diminishing its commercial value. Biosurfactants are chemically diverse molecules that can be produced by several microorganisms and can enable microbial access to hydrocarbons. In order to investigate both microbial activities, function-driven screening assays for biosurfactant production and hydrocarbon biodegradation were carried out from a metagenomic fosmid library.

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Unraveling the microbial diversity and its complexity in petroleum reservoir environments has been a challenge throughout the years. Despite the techniques developed in order to improve methodologies involving DNA extraction from crude oil, microbial enrichments using different culture conditions can be applied as a way to increase the recovery of DNA from environments with low cellular density for further microbiological analyses. This work aimed at the evaluation of different matrices (arenite, shale and polyurethane foam) as support materials for microbial growth and biofilm formation in enrichments using a biodegraded petroleum sample as inoculum in sulfate reducing condition.

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