Metagenomics has risen as a complementary approach to protein engineering for the discovery of industrially relevant enzymes. It is defined as the recovery of genetic information and genes directly from the environment through the direct sequencing of such material. However, the screening of metagenomic libraries in general and for thermostable enzymes in particular is hindered by the lack of suitable expression systems, as up to 70% of the genes encoding thermostable enzymes from T. thermophilus has been shown to improve the success rate in the identification of thermostable enzymes within metagenomes respect to the expression in E. Coli (Angelov et al).