Study of the methanotrophic community present in chronosequence soils from Amazônia.

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). (AU)