The study of metagenomic samples is crucial for understanding microbial communities. In this study, genomic samples of the "El Coquito" hot spring were analysed to identify their metabolic functionality, the thermodynamic restrictions and the influence of biogeochemical cycles. The metabolic functionality was determined assigning reactions and enzymes to the metabolic routes. To determinate the reversibility of the reactions we used the group contribution method. We also performed a topological analysis of the network. We found a total amount of 1930 reactions and 130 metabolic pathways. It was determined that at a pH of 3 there was 256 irreversible reactions and that the reactions involved in energy metabolism belonged to Carbon Fixation, Nitrogen and ammonia assimilation, and sulphur reduction. We found that the "El Coquito" metabolic network is a free scale network and that the clustering coefficients vary if the thermodynamic restrictions are included.