Aislamiento, caracterización e identificación molecular de bacterias provenientes de relaves mineros del sector san carlos de las minas – Zamora Chinchipe

Abstract

The objective of this study was the isolation, characterization and molecular identification of bacterial strains from mining tailings in the San Carlos de las Minas - Zamora Chinchipe sector to evaluate the possible biodegrading potential against mercury concentrations (Hg) and cyanide (CN). The bacterial strains were isolated in nutrient agar by striate seeding; cell morphology was studied based on macroscopic, differential staining and motility tests. Molecular characterization was done by extracting DNA using conventional methods, quality analysis by microvolume spectrophotometry and observation in agarose gel. The 16s and rpoB fragments were amplified by Polymerase Chain Reaction (PCR). DNA sequences were obtained using the Sanger method and high-performance sequencing, assembled with bioinformatics tools and compared with those existing in the gene bank using the platform. Blast® to identify taxonomy. The percentage of mercury and cyanide degradation at three concentrations was evaluated using the broth dilution method, determining the final concentration of each contaminant after five days by standardized methods and the cellular optical density reached by the strains using the absorbance on the scale. From McFarland. It was possible to characterize eight bacterial strains within the genera Pseudomonas sp, Bacillis sp, Staphylococcus sp, Micrococciis sp, and Hydrogenophaga sp with more than 99.32% similarity; same that reached a percentage of cyanide degradation between 7.94% and 66.24% and between 96.31% and 98.80% in the medium with mercury, thus concluding that they can be used for the removal of contaminants from processes miners. It is recommended to study the biological interaction between species and the maximum concentration of contaminants at which microbial growth can be used in bioremediation processes.