438211 Metagenomic Study at Dynamic State to Analyze the Influence of Agricultural Activities in the Structure and Metabolic Functionality of Soil Ecosystems at the Parque Nacional De Los Nevados in Colombia
“4th Conference on Constraint-Based Reconstruction and Analysis (COBRA 2015)”
Metagenomic study at dynamic state to analyze the influence of agricultural activities in the structure and metabolic functionality of soil ecosystems at the Parque Nacional de los Nevados in Colombia
Alvarez-Yela Aa, Restrepo Sb, Husserl Jc, Zambrano Md, Gómez Ja, González-Barrios Aa
aGrupo de Diseño de Productos y Procesos (GDPP), Universidad de los Andes, Bogotá 111711, Colombia.
bLaboratorio de Micología y Fitopatología (LAMFU), Universidad de los Andes, Bogotá 111711, Colombia.
cCentro de Investigaciones en Ingeniería Ambiental (CIIA), Universidad de los Andes, Bogotá 111711, Colombia.
dCORPOGEN, Bogotá 110231, Colombia.
ABSTRACT
Metagenomics enables to study complex microbial interactions within ecosystems through analysis of microbial diversity and metabolic functionality. It seeks to understand how the functionality of the communities defines the nutrients availability in soil by taxonomic analysis, metabolic networks reconstructions and their modeling. The dynamic flux balance analysis (DFBA) of these networks shows the profiles of the metabolic fluxes and metabolite concentrations over time and their behavior under different environmental conditions. In particular, the dynamics of biogeochemical cycles is a consequence of metabolic interactions within ecosystems and may change in response to external perturbations. In this work we present a taxonomic, metabolic and topological analysis of two soils ecosystems at Parque Nacional de los Nevados in Colombia: a not intervened soil and a soil under agricultural activities for Solanum tuberosum crops. We simulated the metabolic behavior at dynamic state using DFBA. The overall analysis showed that agricultural activities increase copiotrophic microorganisms, ammonia-oxidizing archaea and fungi Ascomycetes. Greater functional diversity in not intervened soil was found in terms of evenness of metabolic processes which could let to greater enzymatic flexibility under stress and disturbance conditions while it means a selection process for microorganisms at the intervened soil as a result of intensive use of fertilizers. Metabolic networks showed a free-scale structure which is characteristic of biological systems at the genomic level but with a slightly difference with the features of small networks due to a high variance in the metabolites connectivity distribution, larger diameters and small clustering coefficients. Network of not intervened soil showed greater metabolites degree, longer connections and larger number of nodes which involve a greater metabolic diversity related to shifts in the composition of the microbial communities. Finally, metabolic dynamic analysis showed an intervention effect in the metabolic behavior of the ecosystem and biogeochemical cycles. Not intervened soil has an increased metabolic activity which is variable and fluctuating in time, it has a higher metabolic capacity determined by a higher proportion of metabolic fluxes regulating biogeochemical cycles in a synergistic and interdependent way and it shows an increased production of intracellular metabolites. A lower metabolic activity occurs in the intervened soil with fewer processes coupled together, relevance of biogeochemical processes of nitrogen and carbon cycles and high assimilation rates of extracellular metabolites given by the predominant microbial communities. A high correlation between the microbial communities structure, their metabolic functionality, fluxes and metabolites profiles was found under each intervention conditions.