Detection and evaluation of hydrocarbon mixtures degrading bacteria isolated from desiel polluted soils

الملخص EN

Four hydrocarbon degrading bacterial species were isolated from diesel contaminated soil in Hilla city .The isolates were identified according to cultural and biochemecal tests .It showed that they belong to gram negative species and identified as Pseudomonas aeruginosa ,Serratia marcescens , Pseudomonas flouresence and Alcaligens eutrophus.

The ability of isolates to degrade hydrocarbons were tested towards three HC compounds , engine oil,gasoline and kerosene at 37˚C for 30 days .

These isolates exhibited significant differences in their efficiency of degradation depending on total viable count (CFU/ml) , electrical conductivity (EC μS/cm) and emulsification index (E24).

The more efficient isolate was Pseudomonas aeruginisa as indicated from the increase in the viable count to reach 2.8 × 109 ,3.7 × 109 and 5.3 × 109 (CFU/ml) using a given hydrocarbon component , as a sole source of carbon respectively.

Bacterial consortium of the isolated species was prepared.

The capability of hydrocarbon consumption was studied.

It showed an increase in their activity for biodegradation by increasing of electrical conductivity which reached 82 compared to 52 , 43 , 38 and 34 for the previous mentioned species.