Estudio de microorganismos aislados de un suelo contaminado con desechos derivados de la explotación petrolera y de uno no intervenido.

Abstract

The metabolic pressure generated on the bacterial population in a contaminated soil with petroleum for long periods of time; It is ideal for the search of bacteria capable of degrading hydrocarbons, important in bioremediation processes. The objective of this research was to study the bacterial flora isolated from a contaminated soil with petroleum residues and a soil not intervened. A bacterial isolation was made from six soil samples using medium “PCA” with and without diesel, based on this isolation, 57 clones were selected, these tests were carried out to evaluate the tolerance to diesel, petroleum (0.1%, 25%, 0.5%, 1%, 2%, 4% v/v) and surfactants (1% v/v), in addition tests were carried out in order to determine the growth capacity of these clones in Bushnell-Haas medium using as unique carbon source: diesel, petroleum, benzene, toluene and phenol (1% v / v). Tolerance tests showed that there are more diesel-tolerant clones than petroleum, for the petroleum case the tolerance was similar for the clones isolated from the two types of soil, while in the petroleum case, most of the tolerant clones were obtained from the soil which was not intervened. With respect to the tensactives, most of the tolerant clones to linear sulfonic acid were obtained from the soil not intervened, while, for the quaternary ammonium, the tolerance was similar for the clones isolated from the contaminated and uncontaminated soil. The clone 17 isolated from the contaminated soil presented in three successive peals on the different selective pressures as the sole carbon source, as a result with a superior growth to the rest. It is recommended the use of the clones that showed the highest growth, in consortiums for bioremediation processes in impacted areas with petroleum and its derivatives.