Screening and identification of microorganisms that degrade oil products

Abstract

Today one of the biggest environmental problems is related to hydrocarbon pollution, which is connected to activities from the oil production industry. Accidents of oil spills can pose a danger to aquatic organisms such as fishes or zooplanktons. The oil that reaches the coastal areas can harm coastal organisms like mammals, birds and invertebrates. Nowadays to recover spilled oil from the environment several techniques such as physical, chemical, and biological methods are used. Bioremediation is a promising treatment technology for these contaminated sites because it is cost-effective and converts pollutants into minerals [1-2]. In this work, the microorganisms that could degrade wooden railway sleepers contaminated with oil hydrocarbons were investigated. The sleepers were chopped into small pieces and added into the flasks that contained either LB (Luria Bertani broth for bacteria) or ME (malt extract medium, for fungi). The flasks were incubated overnight at either 37°C for bacteria or 30°C for fungi with shaking, then the cultural medium was spread on the agarized LB or ME (for fungi) media by making serial dilutions. Several passages were performed until pure cultures were obtained and described morphologically. Then the identity of microorganisms was determined by using either bacteria-specific 16S rRNA (27F and 1492R) or fungi-specific ribosomal ITS primers (ITS1 and ITS4). Using this approach, totally 12 microorganisms were isolated as pure cultures, 10 bacterial strains and 2 fungal strains. Among them, 7 bacterial and 1 fungal (yeast) strains were capable of oil degradation as demonstrated by measuring lipase activity using the tributyrin substrate. Further characterisation of isolated strains is currently under way.