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Diversity of methanotrophic bacteria in a chronosequence of preserved and human influenced Amazon ecosystems

Grant number: 10/20007-1
Support type:Regular Research Grants
Duration: July 01, 2011 - June 30, 2013
Field of knowledge:Biological Sciences - Microbiology
Principal researcher:Vivian Helena Pellizari
Grantee:Vivian Helena Pellizari
Home Institution: Instituto Oceanográfico (IO). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Methanotrophic bacteria comprise a group of unique microorganisms, capable of utilizing methane as a sole carbon and energy source, being responsible for the biological oxidation of methane. In soils, they can form a barrier of biological methane oxidation. The Amazon forest has been targeted by researchers studying the global warming, since tropical ecosystems constitute a huge carbon reservoir. In last decades, the region has been deforested and its soils converted to pastures. Methane gas (CH4) is one of the most important greenhouse gases, having a severe impact in the atmosphere. Its rising in recent years has been significant and it has become one of the main concerns in the global warming studies. Methanotrophic bacteria integrate one of the research lines of the Laboratory of Ecology of Microorganisms at the Institute of Oceanography of the University of Sao Paulo, dedicated to understand the ecology of processes involved in the microbial production and consumption of methane. Therefore, the objectives of this work are to verify the occurrence of methanotrophic activity in samples from a cronossequence of soils covered by forests, pastures and by secondary forest, and to evaluate if the soil cover affects the composition of the methanotrophic community. Samples of soils with different vegetation will be collected at Nova Vida Farm, in the center of Rondonia State. In order to measure the methane consumption, soils will be inoculated into sealed flasks containing NMS media and headspace of atmospheric air enriched with 15% methane. The methane consumption will be monitored through gas chromatography with flame ionization detector (GC-FID). DNA extracted from the samples will be screened to the amplification of pmoA gene, that will be used as a phylogenetic marker for the analysis of DNA libraries, DGGE and qPCR. (AU)