BIOREMEDIATION OF CRUDE OIL CONTAMINATED SOIL BY HYDROCARBON DEGRADING BACTERIA

Abstract

Proficiency of hydrocarbon-degrading bacteria useful for eradicating soil pollution stimulated by seepage of petroleum and their derivative substances, therefore, sequestered different bacterial isolates were bear significant merits for utilizing hydrocarbons as an uncommon source of their growth and development. A colorimetric assay was performed at 595 nm wavelength which was subjected to the mineral salt broth with 1% oil (petrol, diesel, and burned out engine oil). This broth having minimum nutrients used by inoculated bacteria in which some isolates were adopted for taking a sufficient amount of either petrol, diesel, or burned-out engine oil as carbon source hence increases its turbidity that was measured in two days time interval up to twelve days of observation. We found that selected isolates were able to degrade burned out engine oil efficiently in contrast to petrol and diesel. At optical density 0.21± 0.13, 0.19±0.08, 0.18±0.09, 0.17±0.12 the result showed by isolatesBI-7, BI-2, BI-4, BI-6goodcompetency to degrade burned out engine oil. On the other hand, maximum diesel and petrol utilized by BI-2 & BI-1 isolate at O.D. 0.09±0.02, 0.05±0.02 was recorded. Most of the bacterial isolates resulted in a positive biochemical test. BI-1 & BI-7 resulted in positive starch hydrolysis test, whereas, all isolates resulted in positive urease test, simultaneously negative results for all isolates obtained when catalase and antibiotic sensitivity test against streptomycin were performed.