Aislamiento y caracterización de clones de bacterias psicrófilas o psicrotolerantes de las lagunas Cuyuc y Colay pertenecientes al Sistema Lacustre de Atillo Bioaumentación mediante el uso de microorganismos autóctonos para el tratamiento de suelos contaminados con hidrocarburos totales de petróleo

Abstract

The objective of the present workhas been the biodegradation of Total Petroleum Hydrocarbons (TPHs) of the environmental liabilities of the AqLab laboratory in Prt. Francisco de Orellana, applying the bioaugmentation technique with Pseudomonas sp (native) and Pseudomonas aeruginosa (commercial). We worked with two treatments from sterilized soil: one inoculated with native strain, and another inoculated with commercial strain, measuring pH, electrical conductivity, organic matter, total organic carbon, nitrogen, phosphorus, and the degradation of TPHs every 20 days for a total period of 80 days; for the third treatment, non-sterilized soil inoculated with the native bacteria was used and monitored for 100 days; the native bacterium was isolated from the laboratory agglomerates in a selective culture medium for Pseudomonas sp, while the activation of the commercial bacteria was carried out following the specifications of the supplier laboratory. Treatments one and two achieved an 84% reduction of the TPHs level on average after 80 days, it is, approximately 10 000 mg/Kg of TPHs in the initial sample, 1500 mg/Kg of TPHs was achieved at end of treatment, the third treatment achieved a 96% reduction in the TPHs level from more than 20000 mg/Kg of TPHs to approximately 1 000mg/Kg of TPHs at the end of the monitoring, thus fulfilling the permissible limits of legal regulations in Ecuador. The results show that the autochthonous strain isolated directly from the agglomerates showed more efficient biodegradation, suggesting to work with native strains to present better adaptability to the contaminated environment, which would guarantee faster, efficient, and environmentally friendly bioremediation processes at lower costs.