Bactérias metanotróficas são capazes de utilizar metano (CH4) como única fonte de carbono e energia, e sua importância no ambiente está relacionada à mitigação das emissões deste gás para a atmosfera. A Amazônia possui importante papel no ciclo do carbono, e o desmatamento da floresta original para conversão a pastagem é um dos principais problemas enfrentados pela Amazônia. O objetivo do projeto foi pesquisar a diversidade metanotrófica a partir de amostras de uma cronossequência de solos de floresta, pastagem e floresta secundária da Amazônia, através de técnicas de cultivo e enriquecimento, construção de bibliotecas do gene pmoA e da técnica de DNA-SIP. As bibliotecas do gene pmoA indicaram a presença das famílias Methylocystaceae e Methylococcaceae. Representando a microbiota ativa (DNA marcado) foram identificadas metanotróficas clássicas das famílias Methylocystaceae e Methylococcaceae, além de grupos de micro-organismos cujo papel no ciclo do CH4 é incerto, como os da Família Methylophilaceae e do Filo Armatimonadetes (OP10). / Methanotrophic bacteria are able to use methane as sole carbon and energy source, and its importance in the environment is related to the mitigation of methane emissions to the atmosphere. The Amazon forest plays an important role in the carbon cycle, and deforestation of the original forest for the conversion to pasture is a major problem faced by the Amazon forest. The objective of this study was to investigate the presence and the diversity of methanotrophic bacteria in samples of chronosequence of forest soils, pasture and secondary forest in the Amazon, through enrichment and cultivation techniques, gene libraries of pmoA gene and application of the DNA-SIP technique. The pmoA gene libraries indicated the presence of methanotrophic bacteria. Representing the active microbiota (labeled DNA), were identified classic metanotrophs belonging from Families Methylocystaceae and Methylococcaceae, and groups of micro-organisms whose role in methane cycle is uncertain, as the Family Methylophilaceae and the Armatimonadetes Phylum (OP10).

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Amazonitic K-feldspar is characteristic of evolved granitic pegmatites of NYF (niobium-yttrium-fluorine) type, associated with A-type granite emplacement. In this work, I focus on four notable examples of such an association: (1) West Keivy, Kola Peninsula, Russia, (2) Saint-Ludger-de-Milot, Quebec, (3) Lac Sairs, Quebec, and (4) Morefield, Virginia. A fifth locality, the Broken Hill metamorphosed exhalative-type volcanogenic deposits in Australia, is an unusual type of amazonitic K-feldspar formed in an ore environment. A total of nineteen samples of amazonitic K-feldspar were characterized geochemically and mineralogically on the basis of X-ray diffraction, electron-microprobe and laser-ablation ICP-MS analyses. Lead, as an essential requirement for formation of the blue-green amazonitic color, has received particular attention. In every case, the analytical data show elevated amounts of Pb and rare alkalis, which strongly partition into the K-rich phase of the perthite intergrowth. Unusual micrometric grains, highly enriched in Pb, are found in cracks in the material from West Keivy. Some of the grains represent a new mineral species, a Pb-dominant feldspar. The presence of amazonitic K-feldspar in a granitic pegmatite is more than a curiosity. It can shed light on important petrogenetic issues such as metasomatic rejuvenation of crustal rocks prior to regional melting in a period of extension.

Bactérias metanotróficas são capazes de utilizar metano (CH4) como única fonte de carbono e energia, e sua importância no ambiente está relacionada à mitigação das emissões deste gás para a atmosfera. A Amazônia possui importante papel no ciclo do carbono, e o desmatamento da floresta original para conversão a pastagem é um dos principais problemas enfrentados pela Amazônia. O objetivo do projeto foi pesquisar a diversidade metanotrófica a partir de amostras de uma cronossequência de solos de floresta, pastagem e floresta secundária da Amazônia, através de técnicas de cultivo e enriquecimento, construção de bibliotecas do gene pmoA e da técnica de DNA-SIP. As bibliotecas do gene pmoA indicaram a presença das famílias Methylocystaceae e Methylococcaceae. Representando a microbiota ativa (DNA marcado) foram identificadas metanotróficas clássicas das famílias Methylocystaceae e Methylococcaceae, além de grupos de micro-organismos cujo papel no ciclo do CH4 é incerto, como os da Família Methylophilaceae e do Filo Armatimonadetes (OP10). / Methanotrophic bacteria are able to use methane as sole carbon and energy source, and its importance in the environment is related to the mitigation of methane emissions to the atmosphere. The Amazon forest plays an important role in the carbon cycle, and deforestation of the original forest for the conversion to pasture is a major problem faced by the Amazon forest. The objective of this study was to investigate the presence and the diversity of methanotrophic bacteria in samples of chronosequence of forest soils, pasture and secondary forest in the Amazon, through enrichment and cultivation techniques, gene libraries of pmoA gene and application of the DNA-SIP technique. The pmoA gene libraries indicated the presence of methanotrophic bacteria. Representing the active microbiota (labeled DNA), were identified classic metanotrophs belonging from Families Methylocystaceae and Methylococcaceae, and groups of micro-organisms whose role in methane cycle is uncertain, as the Family Methylophilaceae and the Armatimonadetes Phylum (OP10).