Dados do Trabalho

Título

NITROGEN-CYCLING GENES AND PROCESSES FOCUSING GREENHOUSE GAS EMISSION IN AGRICULTURAL SOIL

Resumo

Nitrous oxide is one of the most severe greenhouse gases (GHG) due its great warming potential, valued 300 times more powerful than carbon dioxide, and impacts in the nitrogen (N) cycle are mainly supported by shifts in nitrification and denitrification processes carried out by the microbiota in natural and agricultural ecosystems. Apart from gases measurement, the identification of biomarker functional genes related to N cycling processes becomes an important tool to reveal their contribution to GHG generation. Regarding this, metagenomics is one of the best techniques to achieve that purpose. Based on previous metagenome data from sugarcane filter cake (CIT) and soil under sugarcane crop (SCP), this study aimed to do the taxonomic and functional metabolic reconstruction of N metabolism in those ecosystems focusing on nitrogenated GHG emission. To solve this task, gene annotation was performed through scaffolds assembling and ORFs (Open Reading Frames) predictions. Furthermore, the SEED database subsystems approach was used to predict the abundance of metabolic pathways especially those associated to N cycle. Data processing involved 25,000,000 sequences from each metagenome and has allowed the detailing of 11 subsystems associated to N metabolism. CIT and SCP has shown great potential for nitrogen oxides generation besides their capacity for nitrogen fixation, ammonification of nitrate/nitrite, and ammonia assimilation pathways to increment microbial biomass using carbon and nitrogen. The management of sugarcane crop residues and agriculture soil, performed by some sucro-energetic industries, has been a great promoter for GHG emission.

Palavras-chave

sugarcane; filter cake waste; metagenomics; denitrification.

Instituição financiadora

CNPq