Thermophilic Microbial Cell Factory from Antarctica: the case study of Parageobacillus thermantarcticus, an interesting microorganism with great potential biotechnological aims

The knowledge of thermophiles biodiversity could be very useful for the discovery of newmolecules with thermophilic and thermostability properties superior to those currentlyknown and in use. The biggest part of thermophiles studied belongs to the genusGeobacillus. The development of extremophiles from geothermal areas, as a resource fornovel thermostable enzymes, has received attention even in Antarctica, where thepresence of thermophiles has been indicated by the discovery of several geothermalareas. In view of this, a thermophilic bacterium, Parageobacillus thermantarcticus, (DSM9572T) strain M1, isolated from geothermal soil of Mount Melbourne (74°22? S, 164°40?E) in Antarctica (Italian Antarctica Expedition during the Austral summer 1986-1987),was characterized for the production of thermostable enzymatic activities such as anextracellular xylanase, a beta-xylosidase, an intracellular xylose/glucose isomerase, anda protease. The interesting enzymatic pathways present in P. thermantarcticus make thisAntarctic thermophile of great potential in biotechnological applications, not only forindustrial biocatalysis but also for bioprocessing aims. In fact, the optimization ofenzymatic procedures for the conversion of waste lignocellulosic materials in high addedvalue molecules using the xylanolytic enzymatic set of P. thermantarcticus producedextremely interesting results and was recently reported. Moreover, it was demonstratedthat P. thermantarcticus produces two exopolysaccharides (called EPS 1 and EPS 2) thatare responsible for typical mucous colonies. These EPSs were produced using mannoseas a sole carbon and energy source with a yield of 400 mg/L. P. thermantarcticus hasalso been used as a biological model for astrobiology, i.e., the multidisciplinary approachto the study of origin and evolution of life on Earth and in the Universe. It has beendemonstrated that either the viable cells or the spores of P. thermantarcticus to spacesimulation are interesting for the issue of the origin of life. Through the draft genomicsequence of P. thermantarcticus the biotechnology potential and the use of P.thermantarcticus can be increase.