Determinantes genéticos y sus mecanismos de acción implicados en la resistencia bacteriana a metales pesados

Abstract

The purpose of the current research was to identify and describe the main genetic determinants involved in bacterial resistance to heavy metals, as well as their potential use at a biotechnological and environmental level. A bibliographic review was carried out with the information published along the last 10 years in scientific articles with the best quartiles and found in journals with SJR indexing available in the different databases accepted at a national and international level, such as Scielo, Scopus , Elsevier, Redalcy, Science Direct, Latindex among others; this determinesthe current situation about the knowledge on the topic and at the same time it allows making qualitative comparisons between the different results of selected researches. Bacteria are constantly evolving and become more resilient to heavy metals due to the acquisition of genes which allow them to face the toxic effects of these elements. Therefore, the bacterial resistance of genetic determinants was identified for the most toxic heavy metals, such as arsenic, mercury, chromate and cadmium, (ars, aio, mer, chr, cad and czc) respectively, these systems can be found in the chromosome, plasmids, transposons and genomic islands of bacteria. The action mechanism encoding each genetic determinant was defined, mainly the one with regard to the regulation, enzymatic detoxification including the reduction, oxidation, methylation or demethylation and finally the expulsion. These were the main mechanisms found in the different bibliographic references. Finally, the biotechnological and environmental applications of each genetic determinant were compared; so, it was possible to find a wide use in the construction of biosensors and in the generation of genetically modified organisms for the bioremediation of contamination. Thus, it is recommended to continue with similar studies in order to expand the information about different genetic determinants which are resistant to other heavy metals and toxic for living beings.