Associação de bacillus sp. na biorremediação de “óleo queimado” em solo tipo argissolo vermelho

Abstract

Among the possibilities for treating and cleaning environmental contamination by oils, the use of microorganisms to degrade this contaminant has stood out due to its efficiency, cost and practicality. Called bioremediation, this technique aims to degrade the contaminant by non-pathogenic living organisms added to the contaminated environment. Some products already exist with the aim of remedying or reducing contamination, mainly in the area of sewage treatment, with many of them using associations of two or more species of bacteria, including Bacillus subtilis and Bacillus amyloliquefaciens. However, the degree of effectiveness of these associations, both in terms of speed of treatment and range of compounds biodegraded by organisms, has not yet been fully demonstrated, and may be limited by the physiology and competition of the species in use. Therefore, the objective of this work is to test the efficiency of remediation of contamination with lubricating oil of the bacteria Bacillus subtilis and Bacillus amyloliquefaciens alone or in association in a model of soil contamination by lubricating oils. Monitoring of the remediation was carried out using the Bartha Respirometer, a system that serves to solubilize carbon dioxide (CO2) generated in the degradation of the contaminant in a potassium hydroxide solution and subsequently the titration of this solution was carried out, comparing with the titration of the standard/blank system to analyze the production of CO2 produced. Presenting the satisfactory performance of the Bartha system, which was a direct adaptation of the commercial respirometer, enabling a cheaper and more accessible alternative, by 93%, to reproduce research in this field. For biodegradation performance, it was observed that the bacteria in different proportions and variables submitted, presented good potential for hydrocarbon degradation, individually and in the form of an association.