Resumo

Petroleum is an organic compound consisting essentially of a mixture of hydrocarbons. The Brazil has been highlighted in the area of oil exploration, being among the top 12 oil producers in the world. Oil spills causes serious environmental problems due to slow degradation. Bioremediation is a technique of area recovery and contaminated water that has gained great prominence. The objective of this research is to isolate, identify and analyze the biodegradation potential of microorganisms and thus apply them in marine waters contaminated by oil. The oil sample was provided by the Alberto Pasqualini Refinery - REFAP (Canoas / RS). The seawater used in the tests was collected in the city of Shangri-La in the state of Rio Grande do Sul, in the town of Marina-Maristela (-29.829895, -50.049385). We isolated 19 microorganisms from soil samples contaminated with hydrocarbons, containing bacteria, filaments fungus and yeasts. For analyze the petroleum biodegradation potential, we prepared a previous test, which consisted in the inoculation of a controlled amount of microorganisms cells in six different mediums, with and without salinity and nutrients. Then, we analyzed the degradation of oil by analyzing alterations on drop shape and surfactant production and we determinated the optical density of the medium, which indicates the quantity of cells. After this preliminary analysis, we selected three bacteria (MO13, and MO4A MO4B), and three yeasts (B1, B2 and B3). Three strains (MO4a, MO4b and B2) shown to produce rhamnolipid, which is a type of extracellular biosurfactant, whereas B1 and B2 demonstrated a high rate of emulsification. The species were identified by sequencing of conserved regions of DNA. As perspectives, we aim to perform chromatographic analyzes of bioremediation for further characterization and quantification of degradation of the hydrocarbons.