Evaluación de la presencia de microorganismos tolerantes a tensioactivos en afluentes y efluentes de la planta de tratamiento de aguas residuales Villa La Unión, cantón Colta

Abstract

The purpose of the current research was to evaluate the presence of surfactant-tolerant microorganisms in tributaries and effluents of Villa La Unión sewage treatment plant located in Colta County. Two samples a day were collected during a week, in which pH and temperature were measured for their further inoculation in agar PCA, these were incubated at room temperature and 35º C. Then, the selection and purification of the most representative colonies according to distinctive characteristics were carried out, they were characterized in a macro and microscopic way so that, it was possible to determine 6 Gram negative bacterial clones and 4 Gram positive clones. By means of biochemical tests the possible genders were considered, they were: Streptococcus spp., Staphylococcus spp. Micrococcus spp. Pseudomonas spp., and Acinetobacter spp. In addition, the clones were put under surfactant-tolerance evaluation in which quaternary ammonium reflected a clear toxic effect on microbial growth with a tolerance of 1.53%; after the action of diethanolamine surfactant, a tolerant effect of 45.71% was obtained and with the use of sodium lauryl sulfate surfactant, a resistance of 39.28% was found; while, with the nonyl phenol 10 mole surfactant, a tolerance of 45.71% was developed. Through these results, the bacterial clones were able to survive in presence of surfactants, so it is recommended to develop an in-depth evaluation of the different isolated clones, which are effective in the removal of surfactants as a biotechnological tool in the recovery of contaminated water environments.