, 2011). Integrons
are DNA platforms Smoothened Agonist concentration that capture exogenous gene cassettes containing open reading frames (ORFs) and assemble them under the control of a promoter that ensures gene functionality. They are composed of three elements: a gene (intI) encoding an integrase belonging to the tyrosine-recombinase family; a primary recombination site (attI); and an outward-orientated promoter (Pc) that directs transcription of the captured genes (Mazel, 2006). These assembling platforms have a major role in the spread of genes and have been described in Antarctic environments. Several ORFs, homologous to putative or hypothetical transposases, transcription elongation factors, alkylmercury lyase, transcription regulators, penicillin-binding protein, integrases, recombinase/topoisomerase and many unknown proteins, have been described (Stokes et al., 2001; Berlemont et al., 2011). Because integrons are widespread in bacterial populations, it is clear that the pool of ORFs represents a genomic resource for bacterial adaptation because
they are ready for mobilization, reshuffling, and expression of genes. Genomic islands (GIs) are genetic elements, usually acquired by HGT, that also play a major role in microbial evolution and have been found in cold-adapted bacteria. A new bacteriocin biosynthetic cluster selleckchem was located in a GI of Carnobacterium sp. AT7 (Voget C-X-C chemokine receptor type 7 (CXCR-7) et al., 2011). Interestingly, Ayub et al. (2007) found a GI containing polybetahydroxyalkanoate (PHA) biosynthetic genes, numerous mobile elements, an integrase, insertion sequences, a bacterial group II intron, a complete
Type I protein secretion system, and IncP plasmid-related proteins in a mosaic distribution structure, in the Antarctic Pseudomonas sp. 14-3. PHA has a role in stress alleviation, mainly environmental stress. PHA is a carbon and energy storage compound that is accumulated during suboptimal growth conditions, and their degraded elements can be used rapidly for numerous metabolic needs, enhancing fitness during stressful environmental conditions (Kadouri et al., 2005). Taken together, these results support the idea that horizontal transfer of pha genes is a mechanism of adaptability in the Antarctic environment. On the basis of its microbial diversity and extreme environmental conditions, the Antarctic continent has been described as a genomic resource for the identification of novel molecules, in particular cold-active enzymes, for biotechnological uses. These cold-active enzymes have high activities at low temperatures, and this enables their application in certain industrial processes that can be performed at room or tap water temperature, thus allowing energy savings.