Identificación de bacterias aisladas de ecosistemas glaciares, andinos y antárticos

Abstract

Bacteria isolated from glacial, Andean and Antarctic ecosystems were identified. By rep-PCR using the BOX primer, 72 strains were genotypically characterized and a dendrogram was constructed by numerical taxonomy, using the Pearson coefficient and the UPGMA algorithm, obtaining the formation of 10 groups. From these, representatives were selected for the sequencing of the 16S rDNA gene and phenotypic characterization. The phylogenetic analysis of the 16S rDNA gene was performed by calculating the evolutionary distances of Jukes & Cantor and the Neighbor-Joining algorithm, allowing the identification of 11 different species. Of which, strains DG-222 and DG-203 probably belong to new species. However, further studies are necessary to demonstrate this. Through the phenotypic characterization, a dendrogram of numerical taxonomy of phenotypic data was constructed using the SSM coefficient and the UPGMA algorithm, obtaining the formation of 21 phenetic groups with 84,6 percent similarity. Most of the collection was determined as Gram negative, psychrotroph, neutrotolerant, weak halophilic or halophilic. In addition, new physiological characteristics of 4 different species were discovered. The analysis of polyphasic taxonomy with the strains that had fingerprinting patterns similar to the identified species, managed to locate 35 strains according to the molecular characterization. Forming 16 phenetic groups at 90 percent similarity and determining the polyphase taxonomic position of 48,6 percent of the collection. Probably, the diversity of the collection is underestimated and there could be species that have not been identified in this study. It is necessary to carry out a second analysis of the strains that were excluded in the analyzes.