Identification of alkane hydroxylase gene in aliphathic-degrading bacteria isolated from waste oil

Today hydrocarbon pollution is the most important environmental problem. Biological methods can play an important role in removing these contaminants to the environment. This study was aimed to isolate aliphatic compounds degrading bacteria and identify the best degrading strain. Sampling of waste oil depot took in the city of Kerman, Tehran and hydrocarbon-contaminated soils. Alkane degrading bacteria were isolated by using enrichment Bushnel-Hass medium containing hexadecane (as source carbon). In order to identify superior strains, a part of 16SrDNA gene was amplified by PCR and then sequenced. Also, the presence of alkane’s hydroxylase gene in these strains was confirmed by using specific primers. A total of fifteen alakne degrading bacteria were isolated which 8 strains were selected as superior strains. These strains belonged to the genus of Rhodococcus jostii,Stenotrophomonas maltophilia strain M2, Achromobacter piechaudii, Tsukamurell atyrosinosolvens, Pseudomonas fluorescens, Rhodococcus erythropolis,Stenotrophomonas maltophilia strain Q1, Pseudomonas aeruginosa. In this study, the highest growth rate of strians was in concentrations 2.5 percent of hexadecane and the lowest was found in 7 percent. Also, all of the strains have alkane hydroxylase gene. Our results indicated that threre is a high diversity of degradative bacteria in Iran ecosystem and their ability to degrade petroleum wastewater. So, with a proper management of these bacteria can be used to minimize pollution caused by waste oil industries.