|1240-1||HYDROCARBON DEGRADING BACTERIA ISOLATED FROM MARITIME ANTARCTICA SOIL COULD BE ASSOCIATED WITH HORIZONTAL GENE TRANSFER ELEMENTS|
|Autores:||Veronica B. Antelo (IIBCE - INSTITUTO DE INVESTIGACIONES BIOLOGICAS CLEMENTE ESTABLE) ; Silvia Beatriz Batista Cordoba (IIBCE - INSTITUTO DE INVESTIGACIONES BIOLOGICAS CLEMENTE ESTABLE) |
Objective: Physiological characterization of terrestrial microbial communities collected on King George Island (Maritime Antarctica), including the identification of genetic elements that could be involved in the process of horizontal gene transfer.
Background: Human activities carried out in Antarctica must be developed identifying potential environmental impacts. Inevitably, these actions have incorporated hydrocarbons and other pollutans at specific sites on the continent. Microbes may acquire genetic information by horizontal gene transfer (HGT). HGT is recognized as responsible for the distribution of antibiotic resistance and biodegradative encoding genes. This genetic information could enable the recipient organism to survive under specific conditions.
Methods: We have developed a physiological study of microorganism isolated from specific sites on King George Island (South Shetland Islands). In particular, we have analyzed the presence of hydrocarbon assimilation genes. The isolation of bacteria was done using HI, a minimal medium supplemented with 0,2% Antarctic tank diesel as sole carbon source. Trimethoprim resistance (Trimr) of
these isolates was evaluated on Mueller-Hinton medium containing the antibiotic. DNA of the isolates was also used as template in PCR using degenerate primers for amplification of genes encoding naphthalene dioxygenase (ndo).
Results: A collection of 60 bacterial isolates from hydrocarbon contaminated soil was obtained. From this screening we could select 20 Trimr organisms. From 10 isolates we could amplify a fragment of 500 pb, a size consistent with the results obtained previously by Ma et al (2006). Sequence analysis of the amplicons confirmed the presence of ndo genes in six clones of the collection. These organisms were also identified as Pseudomonas sp. by 16S rRNA sequence analysis.
Perspective: The presence of genes encoding for integrase (intI) is being tested. We wish to determine the location and the possible association of intI and ndo genes. We wish to know if an integron-like genetic structure could be involved with the ability to degrade and metabolize diesel as carbon source in these organisms.
Financed by ANII and IAU
Palavras-chave: ANTARCTICA, BACTERIA, HYDROCARBON, HTG