Resumo

ACUNA, Adrián; PUCCI, Graciela; MORALES, María José  e  PUCCI, Oscar. Biodegradation of petroleum and its derivatives by the bacterial community in the soil of the Argentinean Patagonia. Rev. Soc. Ven. Microbiol. [online]. 2010, vol.30, n.1, pp.29-36. ISSN 1315-2556.

The purpose of this study was to characterize a soil sample obtained from an active bioremediation system and determine the capacity of the bacterial community for biodegrading petroleum and its distilled products, and identify the main microorganisms involved in the process. For this object a soil sample was taken with the lanfarming technique and its physical chemical and microbiological characteristics were characterized, as well as the type of hydrocarbons it contained by Soxhlet extraction and silica gel column chromatography. From this sample we also extracted the bacterial community and determined its potential for degrading petroleum, its different fractions and the commercial distilled products obtained from it. We used indirect measurement methods for determining bacterial growth by counting the microorganisms and measuring optical densities. Through these methods we isolated 42 strains and identified them by FAME. The principal results indicated that the soil bacterial community has the capacity for degrading the hydrocarbons in it, mainly the aliphatic fraction as well as the distilled products such as gasoil, kerosene and lubricant oil, while the aromatic and polar fractions and the naphtha distilled product are non degradable. This community is mainly constituted by Rhodococcus erythropolis, Achromobacter xylosoxidans and Brevundimonas diminuta, showing the greatest diversity when the hydrocarbons used as carbon source belong to the aliphatic group. The physical, chemical and microbiological characteristics of the soil indicated that it is possible that an efficient bioremediation of the hydrocarbons present occurs.

Palavras-chave : bioremediation; hydrocarbons; bacterial community.