Abstract

CASTRO-GONZALEZ, Maribeb. Evaluation of the nosZ-type denitrifier community in Isla del Sol water column, Prado reservoir, Tolima. Rev. acad. colomb. cienc. exact. fis. nat. [online]. 2014, vol.38, n.149, pp.385-392. ISSN 0370-3908.

In the present study the genetic diversity of denitrifying communities related to the recycling of greenhouse gas nitrous oxide (N₂O) in Isla del Sol water column, Prado dam (Tolima), was analyzed using the terminal restriction fragment lenght polymorphism analysis of the nosZ functional gene, which encodes the N₂O reduction to N₂ during denitrification. This is the first report demonstrating the presence of nosZ-type denitrifying microorganisms in a Colombian acquatic ecosystem. The results indicated that digestion with the MspI enzyme generated a better nosZ community profile (expresed in an increase of terminal restriction fragments - TRF) than the HhaI enzyme. Besides, the nosZ community had a higher TRF richness and diversity (Shannon index - H'=0.9) at the depth (9m) where suboxic conditions (1.1 mg/L O₂), as well as high nitrate levels (0.78 mg/L) were found, which could favoured N₂O reduction to N₂. These results are the base for future studies on the functionality and significance of such communities for the regulation of N₂O emissions from this dam.

Keywords : Denitrification; reservoir; functional genes; suboxia; hypolimnion.

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