[en] Thermostable enzymes show an enormous importance due to the characteristics, that confer them more stability and also more activity against extreme conditions. Moreover, the enzymes with lipolytic activity have a high capacity and reach in the biotechnological industry, being used in a wide range of industries, such as the food-processing industry, the paper industry, the detergent industry and so on. Hence, it arises interest the bioprospecting of these enzymes in metagenomics libraries from thermal waters, since their great capacity of action in these conditions makes easier their later use in the industry. In this assignment, which is going to be exposed above, we departed from a metagenomics library of DNA from the microbiome of thermal waters from Muíño da Veiga (Ourense) transformed into a strain of Escherichia coli. Starting from 9 initial candidates, whose activity on tributyrin was previously checked, we worked with the one that gave us the least problems to replicate the experiments that are described here. This candidate produced an halo of activity against tributyrin in plaques with LB medium, which finally confirmed its positive activity. Later, we proceeded in order to characterize our enzyme, performing lipolityc activity assays. In this assays we used laurate, octanoate and estearate as substrates. It only showed activity on laurate with which we could deduce that it shows an optimum of activity at the temperature of 90°C (194°F). Finally, we performed the inserted DNA sequencing and, regarding to the results that we obtained from the alignment done with Blastn, we could deduce that it is an organism belonging to the same gender that Conexibacter woesei but a different species.

[gl] As enzimas termoestables presentan unha gran importancia debido ás características que lles confiren maior estabilidade e actividade ante condicións extremas. Por outra banda, as enzimas con actividade lipolítica presentan unha gran capacidade e alcance na industria biotecnolóxica, pois úsanse nun amplo abanico de industrias, como a alimentaria, a de papel, a de deterexentes, etc. De aí que suscite gran interese a bioprospección destas enzimas en metaxenotecas procedentes de aguas termais, xa que a súa gran capacidade de acción en ditas condicións facilita o seu posterior uso na industria. No traballo que se expón a continuación, partiuse dunha metaxenoteca de ADN do microbioma de augas termais procedente de Muíño da Veiga (Ourense) nunha cepa de Escherichia coli cos obxectivos de illar un clon con actividade lipolítica, caracterizar a enzima obtida e secuenciar dito ADN. Partindo de 9 candidatos iniciais, dos que se comprobou previamente a súa actividade en tributirina, traballamos có que menos problemas nos presentaba á hora de replicar os experimentos aquí descritos. Dito candidato mostrou halo de actividade fronte á tributirina nas placas con medio LB, o que confirmou como positivo en dita actividade. Posteriormente procedemos a caracterizar a nosa enzima, realizando ensaios de actividade lipolítica nos que usamos laurato, octanoato e estearato como substratos da reacción. Só presentou actividade co laurato, co cal poidemos deducir que presenta un óptimo de actividade a unha temperatura de 90°C. Finalmente, realizouse a secuenciación do ADN insertado e, a partir dos resultados obtidos no aliñamento realizado co Blastn, poidemos deducir que se trata dun organismo pertencente ao mesmo xénero que Conexibacter woesei, pero non á mesma especie.