DEGRADATION OF LONG CHAIN ALKANES BY NEWLY ISOLATED BACTERIA

Background and Aim:Long chain alkanes are significant proportion of the oil. Soil and water pollution with these compounds, have many environmental consequences. Separation of microorganisms with the ability to decompose these alkanes, as followed in this research, is a suitable and biocompatible method for solving environmental problems of the oil industry.Methods:Soil was removed from a depth of 20 cm in a contaminated area of Abadan and it analyzed by Gas chromatography-mass spectrometry. 0.5 gr of soil was added to 100 mL of nutrient broth containing two anti-fungal antibiotics; nystatin and cycloheximide, each at a concentration of 50 mg/L, and incubated in a shaking incubator at 30°C overnight. Then, n-Dodecane (C12H26), n-Tetradecane (C14H30) and n-Icosane (C20H42) were separately added to mineral salt medium (MSM), in the presence of 0.5%w/v SDS. The flasks were inoculated with 2% bacterial stock and incubated at the same condition. Each experiment was repeated twice. Absorption in 660 nm was considered as a scale of the bacterial growth with alkane consumption.Results:According to the GC-MS results, C12 ,C14 ,C16 and C20 in the soil sample was 2.5%, 2.2%, 1.9% and 2.3%w. Mean absorption of the growth media with three carbon sources i.e. C12 ,C14 and C20 after two weeks was 0.15, 0.13 and 0.95.Conclusion:It could be hoped that the isolated bacteria would have the potential for bioremediation of oil polluted areas.

Keywords:

Hydrocarbons , Bioremediation , Mineral Salt Medium