Remarkable ecological and physiological diversity of the hyperthermophiles populating neighboring solfataric pools revealed by metagenomic analysis

The study of the complex communities of hyperthermophiles, composed of Bacteria, Archaea, and viruses, populating volcanic sites is of interest to understand their adaptation and evolution to extreme conditions and as a rich source of biocatalysts [1, 2]. In fact, the intrinsic stability of their enzymes to common protein denaturants made them interesting tools for biotransformations in industrial applications. In the framework of the discovery of new enzymes for biocatalysis and biotransformations, we decided to explore the diversity of the solfataric field of Pisciarelli, Agnano (Naples, Italy), by performing a metagenomic analysis of the microbial community living in two mud/water pools that, although distant only 4.0 meters, greatly differ in both temperature and pH (T=85°C and pH 5.5; T=94°C and pH 1.5, for Pool1 and Pool2, respectively). In particular, DNA from Pool1 was extracted from the mud/water suspension while Pool2 DNA was obtained from the sediment. The deep sequencing by Illumina technology and the following in-silico analysis showed that the phylum Crenarcheaota was prevalent, but with great genera variance in the two pools according to the different environmental T and pH. The analysis of the functional categories revealed that genes involved in the carbohydrate metabolism were prevalent, followed by amino acid metabolism and by membrane transporters. The detailed phylogenetic and physiological analysis of the samples will be discussed together with the possible mechanisms of selection occurred in the two extremophilic environments. Bibliography 1. Cobucci-Ponzano B., Aurilia V., Riccio G., Henrissat B., Coutinho P.M., Strazzulli A., Padula A., Corsaro M.M., Pieretti G., Pocsfalvi G., Fiume I., Cannio R., Rossi M., and Moracci M.: J Biol Chem, 2010, 20691-20703. 2. Cobucci-Ponzano, B., Conte, F., Strazzulli, A., Capasso, C., Fiume, I., Pocsfalvi, G., Rossi, M., Moracci.: M. Biochimie, 2010, 92, 1895-907