The contamination of soil by petroleum hydrocarbons, like spent engine oil (SEO), is one of the main environmental problems in Mexico and the world. SEO is a mixture of hydrocarbons generated during the lubrication cycle of the engine, which causes many problems such as the inhibition of life in the soil, the reduction of agricultural production, and public health problems. In this work, bacteria strains are isolated from soil contaminated with SEO from an automotive mechanic workshop in Sonora, Mexico. First, the contaminated soil samples were characterized by determining pH, moisture content, electrical conductivity, organic matter content, and the quantification of total petroleum hydrocarbons (TPH), by a gravimetric method. Ten different bacterial strains were isolated in diesel-agar plates, based on colonial morphology. Then, they were subjected to gram stain and biochemical tests, for their identification. After that, the bacterial strains were tested to select the most convenient to form a bacterial consortium for the bioremediation of contaminated soil, through an evaluation of lipolytic activity, using rhodamine B agar, to confirm the presence of lipase enzymes and surfactants, and tolerance to hydrocarbons, using diesel as the hydrocarbon source in diesel-agar, and as the sole carbon source in mineral medium agar (MM agar). Three bacterial strains, labeled as C5, C7, and C8 were selected as the most suitable to form a bacterial consortium in future research because they showed lipolytic activity and tolerance to hydrocarbons.

https://zoom.us/j/94047390801?pwd=MHlCdFU1YWdxUndJcUhnaVJqYUlRUT09